WO1996021868A1 - Glass matrix doped with activated luminescent nanocrystalline particles - Google Patents

Glass matrix doped with activated luminescent nanocrystalline particles Download PDF

Info

Publication number
WO1996021868A1
WO1996021868A1 PCT/US1995/009119 US9509119W WO9621868A1 WO 1996021868 A1 WO1996021868 A1 WO 1996021868A1 US 9509119 W US9509119 W US 9509119W WO 9621868 A1 WO9621868 A1 WO 9621868A1
Authority
WO
WIPO (PCT)
Prior art keywords
glass
luminescent
semiconductor particles
glass matrix
activator
Prior art date
Application number
PCT/US1995/009119
Other languages
French (fr)
Inventor
Alan L. Huston
Brian L. Justus
Original Assignee
The Government Of The United States Of America, Represented By The Secretary Of The Navy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Government Of The United States Of America, Represented By The Secretary Of The Navy filed Critical The Government Of The United States Of America, Represented By The Secretary Of The Navy
Priority to CA002213477A priority Critical patent/CA2213477C/en
Priority to EP95928090A priority patent/EP0871900B1/en
Priority to AT95928090T priority patent/ATE210307T1/en
Priority to JP52163196A priority patent/JP3724807B2/en
Priority to DE69524458T priority patent/DE69524458T2/en
Publication of WO1996021868A1 publication Critical patent/WO1996021868A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00Nanooptics, e.g. quantum optics or photonic crystals
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01TMEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/02Dosimeters
    • G01T1/10Luminescent dosimeters
    • G01T1/11Thermo-luminescent dosimeters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01TMEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/02Dosimeters
    • G01T1/10Luminescent dosimeters
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2202/00Materials and properties
    • G02F2202/36Micro- or nanomaterials

Definitions

  • the present invention relates generally to luminescent glasses, and more specifically to glasses doped with nanocrystalline semiconductor particles and an activator for luminescence.
  • inorganic solids The luminescence of bulk semiconductor and insulator materials (herein generally referred to as inorganic solids) has been intensively studied for decades. The nature of the luminescent centers in these materials can be broadly classified into several categories, 1) emission due to recombination of electron-hole pairs; 2) exciton emission; 3) broadband emission due to impurities with filled electronic shells; and 4) narrowband emission due to impurities with incomplete electronic shells, such as transition metal and rare earth ions.
  • the impurity atoms and ions are referred to as activators (and/or co-activators if more than one impurity is required) .
  • Luminescent inorganic solids, particularly those activated by added impurities, are known as phosphors. There are countless important commercial and military applications for a wide variety of phosphor materials. A brief (and necessarily incomplete) list of phosphor applications follows: 1)Cathodoluminescence
  • Cathodoluminescent phosphors are used in cathode ray tubes (CRT's), including television sets, radar screens and oscilloscope displays.
  • Typical cathodoluminescent phosphors are sulfides of cadmium and zinc. The colors emitted by a color television screen are due to the interaction of accelerated electrons with phosphors activated with impurities selected for the frequency (color) of their luminescence. 2) Electroluminescence
  • Electroluminescence is the generation of light upon the application of an electric field across a material.
  • the applications for electroluminescent phosphors are numerous, including, for example, lighting and display technologies.
  • Thermoluminescent phosphors emit light when heated. Emission occurs due to the release (detrapping) of trapped electrons that result from prior excitation of the phosphor using ultraviolet (UV) or ionizing radiation.
  • Thermoluminescent materials are used as dosimeters to monitor the exposure of personnel and equipment to high energy ionizing radiation.
  • Radioluminescent phosphors emit light upon exposure to high energy ionizing radiation and are often referred to as radiation scintillators.
  • Inorganic scintillators are used to detect the presence of ionizing radiation in many venues including monitoring of the environment and the protection of personnel at nuclear installations.
  • Infrared (IR) stimulable phosphors emit visible light upon exposure to infrared radiation. This emission occurs due to the migration and recombination of trapped electrons which previously formed upon excitation of the phosphor by UV radiation. These phosphors are similar in principle to the thermoluminescent phosphors in that the excitation energy of the UV radiation is stored (trapped) in the phosphor. These phosphors have many applications including, for example, the detection and imaging of IR radiation, and optical data storage.
  • the powder appears white when illuminated with visible light due to the highly efficient scattering caused by the small particles. Because of the efficient scatter, the phosphor powder is not transparent to its own luminescence. For this reason, the phosphor must be used in a very thin layer or its luminescence would be effectively attenuated.
  • a final disadvantage of the powder phosphor is its mechanical fragility. It must be protected somehow and usually cannot withstand high temperatures, hostile chemical environments, or abrasions. Severe limitations are often placed on the functionality of the phosphor due to the inability to manufacture the material in a transparent state. The problems cited above are not unique to any one application, but are shared by many phosphors in many applications.
  • the crystals may be mechanically fragile or susceptible to thermal shocks. Some crystals are hygroscopic, or cannot withstand even mildly corrosive chemical environments. Some phosphors become health hazards as they age due to the diffusion of toxic materials out of the crystal.
  • the second technique has been to embed the micron-sized crystalline phosphors in a glass (or polymer) matrix, Although polycrystalline phosphors have been incorporated in this way in both low-melting glass and polymer hosts, the optical problems (scattering) associated with the micron sized particles are not improved.
  • the effects of the small dimensions on the physical properties are often referred to as quantum confinement effects and the nanocrystals themselves are often referred to as quantum dots.
  • Nanocrystals of both I-VII and II-VI semiconductors have been grown in alu inoborosilicate glasses using the diffusive precipitation method described above.
  • II-VI semiconductor quantum dots have been prepared using a variety of sol-gel glass fabrication methods as well as radiofrequency (rf) sputtering methods.
  • II-VI semiconductor quantum dots have been deposited into porous VycorTM (Corning, Inc) glass using precipitation reactions as well as metalloorganic chemical vapor depositions (MOCVD or CVD) methods, III-V semiconductor quantum dots have also been prepared in porous VycorTM glass using several CVD techniques.
  • a glass with inorganic nanocrystals including an activator for the nanocrystals.
  • fabrication is accomplished by deposition of the activator and nanocrystalline semiconductor particles into a porous glass matrix.
  • Fig. 1 shows the thermoluminescence signal as a function of copper sulfate concentration for a sample made according to the procedures of Example 1, but with varying concentrations of copper sulfate in the copper sulfate doping solution.
  • the solid line shows the fluorescence excitation, while the dotted curve shows the fluorescence emission.
  • Fig. 2 shows the thermoluminescence signal as a function of zinc nitrate concentration for a sample made according to Example 1, but with varying concentrations of zinc nitrate in the zinc nitrate doping solution.
  • Fig. 3 shows the effect of ZnS concentration on the positions of the thermoluminescence glow peaks.
  • Curve (a) shows the typical thermoluminescence observed at low concentrations (corresponding to 1 g/100 ml zinc nitrate in the doping solution) of copper activated (1 mg Cu/ml doping solution) ZnS nanocrystals in VycorTM glass, while curve (b) shows the growth of a higher luminescent glow peak in a higher concentration (corresponding to 10 g/100 ml zinc nitrate in the doping solution) of copper activated (1 mg Cu/ml doping solution) ZnS nanocrystals in VycorTM glass.
  • Fig. 4 shows the excitation and emission spectra of a copper activated ZnS/VycorTM glass composite phosphor made according to Example 1.
  • Fig. 5 shows the excitation and emission curve of a europium activated KCl/VycorTM glass composite phosphor made according to Example 2.
  • the nanocrystalline inorganic solid/glass composite phosphors are fabricated by deposition of the inorganic solid and the activators within a porous glass matrix.
  • the deposition can be accomplished using known chemical methods for doping glasses, such as, for example, precipitation from a liquid phase solution, or CVD. Often, the most convenient method will be precipitation from a liquid phase solution.
  • the exact deposition process used and the parameters employed for deposition are not critical, provided that the deposited materials are nanocrystalline and the glass retains its porosity.
  • the size of the deposited crystals is controlled by the pore size of the glass into which the crystals are deposited. The pores restrict the growth of the deposited crystals so that the deposited crystals have a diameter smaller than that of the pore in which they precipitate.
  • the pores in a porous glass are in reality tortuous channels, sometimes interconnected, which behave like pores.
  • the concentration of the dopants within the glass becomes too great for the average effective pore size, the nanocrystals will grow through the channels, interconnect, and develop into large crystals that reduce the transparency of the glass.
  • a thermal heat treatment may be used to promote diffusion of the activators in the nanocrystals and to control the nature and quality of the crystalline phase. This heat treatment is performed at a temperature sufficient to substantially enhance diffusion of the activators.
  • the activation temperature is also selected to partially, or perhaps even fully, consolidate the porous glass. If desired, the porous glass can be activated at a temperature below that needed to consolidate the glass. The activation temperature, however, should not be so high as to liquify the glass. For 7930 VycorTM glass (Corning, Inc.), an activation temperature of typically from about 800 to about 1100°C may be used. The activation temperature must be below the melting temperature of the glass.
  • Annealing i.e., accompanied by at least partial consolidation of the glass (collapsing of at least some of the pores), requires temperatures above the T of the glass.
  • the time for activation may be varied depending upon what, if any, degree of consolidation is required. While the order in which the components are mixed is not critical, all components of the glass, must be present during the activation step.
  • Suitable porous glasses are amorphous matrices with densely packed, tortuous, nanometer-sized, interconnecting pores or channels. The exact chemical compositon is not critical.
  • porous VycorTM Corning, Inc.
  • VycorTM glass is a 96% silica glass obtained by heat treating a borosilicate glass to separate the boron and silicate phases and then subjecting the heat treated glass to an acid etch, thereby removing most of the boron phase and leaving the porous 96% silica glass.
  • the VycorTM glass can be obtained in a wide variety of sizes or shapes, including sheets, rods, tubes, and irregular shapes.
  • Suitable porous glass hosts can also be prepared using well-known sol-gel glass technology. These glasses are prepared by the acid catalyzed or base catalyzed hydrolysis of metallic esters or alkoxides.
  • Single component or multiple component glasses can be prepared and include, for example, silicate, titanate, germanate and zirconate glasses.
  • porous sol-gel glasses may also be manufactured in a wide variety of shapes and sizes as well as in thin films. Porous glass matrices that may be made by the sol-gel process include pure Si0 2 , pure A1 2 0 3 (alumina glass) , pure Ti0 2 and mixtures thereof in varying proportions to provide glasses with varying properties.
  • the pores typically average about 10 to about 100 A in diameter, more often about 40 to about 75 A in diameter and most often about 40 to about 50 A in diameter.
  • Vycor glassTM (Corning 7930) has an average pore size of about 40 A diameter.
  • Average pore sizes of less than 40 Angstrom diameter can be obtained using sol-gel derived glasses.
  • Average pore sizes of less than 10 A diameter are not practical because it is difficult to diffuse solutions into the pores.
  • Average pore sizes that are larger than 100 A in diameter may be too large to assure nanocrystal formation, depending on the concentration of the activator and semiconductor employed. The optical quality of glasses prepared from larger pore sizes is diminished.
  • the size distribution of the particles should be selected to maintain the transparency of the glass to its own luminescent emissions.
  • the activator should preferably not form particles having diameters greater than about 100 A. Particles having a diameter of greater than 100 A may reduce the transparency of the glass matrix, and thus their presence within the glass should be minimized.
  • a pore density of 25 to 30 volume percent is ideal because it allows for the formation of isolated and separated nanocrystalline structures. If the void volume is too high, the semiconductor crystallites may be too close together and merge to form particles larger than nanocrystals. Lower pore densities simply reduce the amount of semiconductor material that can be introduced to the glass. This situation may be desirable for certain applications such as doped fiber-optic cables.
  • the nanocrystalline nature of the semiconductor particles in the material of the present invention is critical. Because of the small size of nanocrystals, glass doped therewith maintains its transparency. If the nanocrystals are sufficiently small (below about 80 A, with a narrow size distribution so that few, if any particles are more than 120 A) they may become quantum-confined. The effects of this quantum confinement are favorable in many circumstances, although quantum-confined semiconductor particles are not required to obtain many benefits of the present invention.
  • the selection of suitable inorganic solid phosphor materials to be deposited in porous glass in an effort to fabricate nanocrystalline phosphor/glass composites is guided by previous knowledge about the most useful and efficient bulk phosphors.
  • phosphors manufactured using many combinations of inorganic solids and activators.
  • Some of the most useful phosphors are sulfides of zinc or alkaline earths such as calcium, magnesium and strontium, activated with transition metal or rare earth ions.
  • Activated ZnS phosphors have found wide utility in a variety of applications including cathodoluminescence, radioluminescence, electro- luminescence, and IR sensitivity.
  • Different activators and/or co-activators have been identified and their relative concentrations optimized for the desired application.
  • useful ZnS phosphors have been manufactured using activators and co- activators (when required) selected from the following: rare earth ions, silver, copper, lead, chloride, and manganese ions. This list is by no means complete.
  • Sufficient activator or (activator/co-activator) should be employed in the glass to provide an activator concentration effective to luminescently activate the semiconductor nanocrystals, i.e., render the nanocrystalline semiconductor particles capable of emitting light in the visible or infrared range in response to electronic excitation at an appropriate wavelength.
  • concentrations and identities of the dopants result in different physical and optical properties of the nanocrystalline semiconductor doped glass.
  • copper activated zinc sulfide glasses display the following trends: increasing the concentration of copper sulfate in the doping solution from zero to approximately 0.1 gram in 100 cubic centimeters of water shows an increase in thermoluminescence with increasing copper concentration.
  • thermoluminescence intensity decreases (Fig. 1) .
  • high concentrations of ZnS lead to a decrease in the thermoluminescence emission from the glass (Fig. 2) .
  • Intermediate concentrations of ZnS lead to thermoluminescent glow peaks at higher temperatures (Fig. 1)
  • the luminescent nanocrystalline semiconductors particles may communicate with each other, slightly changing their electronic energy levels and characteristic spectra. Also, to maintain the transparency of the glass to its own fluorescence, the number of activator particles having a particle diameter greater than about 100 A should be minimized in the glass. It may even be desirable to avoid the formation of any activator particles having a diameter of greater than about lOoA. Possibly, but not necessarily, the activator may substitute into the crystal lattice of the nanocrystalline semiconductor particles. However, activation might be the result of proximity effects between the activator and the nanocrystalline semiconductor particles.
  • the activated nanocrystalline inorganic solid phosphors of this invention may be manufactured, for example, from type II-VI semiconductors, of which ZnS is an example, type III-V semiconductors, of which gallium arsenide is an example, type IV-IV semiconductors, of which silicon is an example, alkali halides, of which potassium chloride is an example, or alkaline earth sulfides, of which calcium sulfide is an example.
  • the activator and/or co-activator ions can be chosen from the rare earth metals, of which europium is an example, or the transition metals, of which manganese is an example.
  • Co- activators also often include halogen ions, of which chloride is an example. The use of europium as an activator results in a mixed blue and red luminescence.
  • Doped glasses according to the present invention can exhibit cathodoluminescence, electroluminescence, thermoluminescence, radioluminescence or sensitized luminescence.
  • the emission of light after excitation can be immediate or delayed (energy trapping) .
  • the exact type of luminescence observed will depend, in a characteristic way, upon the semiconductor and activator used, as well as the concentration of those materials within the glass.
  • the type of luminescence observed depends on the excitation conditions.
  • the chemistry of the phosphor may be manipulated and predicted to enhance a particular type of luminescence.
  • the following is a generalized exemplary procedure for making a doped glass according to the present invention.
  • the purpose of this generalized procedure is illustrative only.
  • the doping method illustrated is precipitation from solution, it should be understood that other doping methods, dopants and porous glasses may be used.
  • a piece of porous glass such as porous VycorTM glass, is immersed in an aqueous solution of a water soluble metal salt such as zinc nitrate.
  • a water soluble metal salt such as zinc nitrate.
  • the solution is allowed to diffuse completely throughout the porous glass.
  • the metal salt solution concentration can range between zero and the solubility limit of the salt (1.8 grams per cubic centimeter of water for zinc nitrate) .
  • a metal sulfide dopant such as zinc sulfide, is desired it may be formed in situ , for example, by the addition of an aqueous solution of thioacetamide to the solution of the water-soluble salt.
  • the thioacetamide/metal salt solution reaction proceeds for a period of time ranging from one hour to several days, depending on the temperature of the solution. A lower temperature (about 25'C to about 50 ⁇ C) results in a slower reaction and assures a uniform distribution of metal sulfide throughout the porous glass piece.
  • An alternative method for producing a metal sulfide is to expose the metal doped glass piece to hydrogen sulfide (H 2 S) gas for a period of approximately one hour. The H 2 S gas diffuses quickly throughout the porous glass and reacts with the deposited metal salt.
  • the porous glass, containing the desired dopant is next immersed in an aqueous solution of metal salt activator, such as copper sulfate or europium chloride.
  • the concentration of the metal salt activator can range between zero and the solubility limit of the salt (approximately 0.4 grams per cubic centimeter for copper sulfate, although no enhancement beyond about 0.2 g ml is observed in the case of copper sulfate) .
  • This solution is allowed to diffuse throughout the porous glass, typically at about room temperature. The glass is then dried slowly, over a period of one hour, to prevent cracking of the glass.
  • the temperature is raised slowly (several hours) to approximately 300 degrees centigrade and then the temperature is increased more rapidly (one hour) to typically no greater than about 1100"C - 1150'C.
  • the glass is maintained at high temperature for a period of three to 24 hours to fully activate the glass phosphor.
  • the glass is cooled to room temperature over a period of one to three hours.
  • the resulting glass is highly luminescent when exposed to radiation wavelengths that overlap the absorption band of the doped, activated glass. For ZnS activated with copper, exposure to ultraviolet wavelengths of less than 300 nm, results in an intense blue-green luminescence.
  • 0.1 g of zinc nitrate hexahydrate were dissolved in 100 ml distilled water. To the resulting solution were added 1 cc concentrated nitric acid. 1 g of porous Corning 7930 VycorTM glass were then added to the acidified solution, in which it was allowed to remain for 1 to 2 hours to allow complete diffusion of the zinc nitrate solution throughout the glass. The glass was then removed from the solution and dried.
  • a thioacetamide solution was prepared by dissolving 1.0 g thioacetamide in 100 ml distilled water, adding 1 ml concentrated nitric acid. The thioacetamide solution was then placed in a constant temperature bath set to 30'C. The dried zinc-loaded porous glass was then placed into the sulfide solution and allowed to react therewith for at least 10 hours to form nanocrystalline ZnS. The porous glass sample was then removed from solution and dried.
  • copper sulfate 0.01 g copper sulfate was dissolved in 100 ml water.
  • the zinc sulfide-containing glass sample was then placed in the copper sulfate solution and allowed to remain there for 1 to 2 hours to allow complete diffusion of the copper sulfate solution throughout the porous glass.
  • the copper doped zinc sulfide glass sample was then removed from the copper sulfate solution and dried.
  • the dried zinc sulfide/copper-doped porous glass was then placed in an oven at room temperature.
  • the oven temperature was then increased at a rate of about l'C/minute up to a temperature of 300 * C. Over the course of an next hour, the temperature of the oven was then raised to 1150*C.
  • the sample was baked at 1150°C for at least 3 hours and then allowed to cool to room temperature (Cooling may occur either by shutting off the oven and allowing the sample to cool within, or by removing the sample from the oven) .
  • the absorption spectrum of the ZnS phosphor glass exhibited a maximum at approximately 260 nm, with a broad tail extending to approximately 320 nm.
  • This absorption feature was characteristic of excitonic absorption within ZnS nanocrystallites (quantum dots) .
  • the location of the absorption peak reflected the blue shift of the exciton energy due to quantum confinement of the excitons.
  • the width of the absorption feature reflected the size distribution of the quantum dots in the glass composite.
  • Fig. 4 shows the emission and fluorescence excitation spectra of a sample of the copper activated ZnS quantum dot phosphor composite.
  • the solid curve was obtained by scanning the optical excitation source from 240 nm to 350 nm and monitoring the total emission.
  • the heavy dashed curve is the emission curve obtained by exciting the sample at 266 nm.
  • An elemental analysis of the sample indicated that the individual concentrations of zinc sulfide and copper were less than 5 ppm.
  • Example 2 - KC1 activated with europium ions, manufactured in porous Vycor glass
  • Example 1 The procedure used in Example 1 was used, except that the glass was directly doped using a solution of 1 g KC1 in 100 ml of water followed by doping with 1 g EuCl solution in 100 ml of water. No sulfides were used.
  • the absorption spectrum of the KC1 phosphor glass exhibited a maximum at approximately 240 nm, with a broad tail extending to approximately 300 nm. This absorption feature was characteristic of absorption by europium ions within the crystal lattice of the alkali halide. The location and width of the absorption peak reflect the nature and the influence of the crystalline host environment seen by the europium ions. After excitation of the nanocrystalline phosphor by the UV light, emission occurs from the excited europium ions.
  • the emission is characterized by a broad band centered at approximately 450 nm due to emission from Eu *2 ions, in addition to a narrow peak at 615 nm due to Eu 43 emission.
  • the emission and fluorescence excitation spectra are shown in Fig. 5.
  • the heavy solid curve was obtained by scanning the optical excitation source from 224 nm to 350 nm and monitoring the total emission.
  • the light solid curve is the emission spectrum obtained by exciting the sample at 266 nm.

Abstract

A luminescent glass includes nanocrystalline semiconductor particles, such as ZnS nanocrystals, and an activator, such as copper, for the particles. The glass is made by depositing the nanocrystalline semiconductor particles and the activator within a porous glass matrix, such as 7930 VycorTM and then thermally activating the glass. The porous glass matrix may be at least partially consolidated or may be allowed to remain porous. The nanometer particle size permits the luminescent glasses of the present invention to be transparent to its luminescent emsissions.

Description

GLASS MATRIX DOPED WITH ACTIVATED LUMINESCENT NANOCRYSTALLINE PARTICLES
Background of the Invention
1. Field of the Invention
The present invention relates generally to luminescent glasses, and more specifically to glasses doped with nanocrystalline semiconductor particles and an activator for luminescence.
2. Description of the Background Art The luminescence of bulk semiconductor and insulator materials (herein generally referred to as inorganic solids) has been intensively studied for decades. The nature of the luminescent centers in these materials can be broadly classified into several categories, 1) emission due to recombination of electron-hole pairs; 2) exciton emission; 3) broadband emission due to impurities with filled electronic shells; and 4) narrowband emission due to impurities with incomplete electronic shells, such as transition metal and rare earth ions. The impurity atoms and ions are referred to as activators (and/or co-activators if more than one impurity is required) . Luminescent inorganic solids, particularly those activated by added impurities, are known as phosphors. There are countless important commercial and military applications for a wide variety of phosphor materials. A brief (and necessarily incomplete) list of phosphor applications follows: 1)Cathodoluminescence
Cathodoluminescent phosphors are used in cathode ray tubes (CRT's), including television sets, radar screens and oscilloscope displays. Typical cathodoluminescent phosphors are sulfides of cadmium and zinc. The colors emitted by a color television screen are due to the interaction of accelerated electrons with phosphors activated with impurities selected for the frequency (color) of their luminescence. 2) Electroluminescence
Electroluminescence is the generation of light upon the application of an electric field across a material. The applications for electroluminescent phosphors are numerous, including, for example, lighting and display technologies.
3)Thermoluminescence
Thermoluminescent phosphors emit light when heated. Emission occurs due to the release (detrapping) of trapped electrons that result from prior excitation of the phosphor using ultraviolet (UV) or ionizing radiation. Thermoluminescent materials are used as dosimeters to monitor the exposure of personnel and equipment to high energy ionizing radiation.
4)Radioluminescence
Radioluminescent phosphors emit light upon exposure to high energy ionizing radiation and are often referred to as radiation scintillators. Inorganic scintillators are used to detect the presence of ionizing radiation in many venues including monitoring of the environment and the protection of personnel at nuclear installations.
5)Sensitized luminescence
Infrared (IR) stimulable phosphors emit visible light upon exposure to infrared radiation. This emission occurs due to the migration and recombination of trapped electrons which previously formed upon excitation of the phosphor by UV radiation. These phosphors are similar in principle to the thermoluminescent phosphors in that the excitation energy of the UV radiation is stored (trapped) in the phosphor. These phosphors have many applications including, for example, the detection and imaging of IR radiation, and optical data storage.
Many of the inorganic solid phosphors used in the applications cited above are available only as polycrystalline powders with particle dimensions ranging from one to tens of microns. An intensive area of research for literally decades has been the search for improvements in the structure and form of the phosphors. Attempts to grow single crystal phosphors, thin film phosphors, or phosphors embedded in glass have met with varying degrees of success. To better illustrate the motivation for these efforts, consider a typical polycrystalline phosphor, available as a powder with particle dimensions of 1 μm or greater. Large crystals often cannot be grown due to the very high melting point of the inorganic solid and the presence of the activator metal ions. The powder appears white when illuminated with visible light due to the highly efficient scattering caused by the small particles. Because of the efficient scatter, the phosphor powder is not transparent to its own luminescence. For this reason, the phosphor must be used in a very thin layer or its luminescence would be effectively attenuated. A final disadvantage of the powder phosphor is its mechanical fragility. It must be protected somehow and usually cannot withstand high temperatures, hostile chemical environments, or abrasions. Severe limitations are often placed on the functionality of the phosphor due to the inability to manufacture the material in a transparent state. The problems cited above are not unique to any one application, but are shared by many phosphors in many applications. Even in those cases where it is possible to grow the phosphor in a single crystal, many problems remain. The crystals may be mechanically fragile or susceptible to thermal shocks. Some crystals are hygroscopic, or cannot withstand even mildly corrosive chemical environments. Some phosphors become health hazards as they age due to the diffusion of toxic materials out of the crystal.
In order to avoid some of these difficulties, researchers have worked to incorporate polycrystalline phosphors into glass matrices. Historically, two basic approaches have been used. Attempts were made to grow phosphor nanocrystals from the substituent inorganic material and activators) by diffusive precipitation from a glass melt as a result of striking (heat treating) the glass. This approach did not meet with success since the activator ions are usually quite soluble in the glass matrix and prefer to remain in the glass rather than precipitate out with the crystal. The second technique has been to embed the micron-sized crystalline phosphors in a glass (or polymer) matrix, Although polycrystalline phosphors have been incorporated in this way in both low-melting glass and polymer hosts, the optical problems (scattering) associated with the micron sized particles are not improved.
B. Nanocrystalline inorganic solids
Nanometer-sized crystals of inorganic solids, and, in particular, semiconductors, have been intensively studied over the past decade due to the interest in the basic physical properties of the nanocrystals and their potential uses in electronic and optical devices. The effects of the small dimensions on the physical properties are often referred to as quantum confinement effects and the nanocrystals themselves are often referred to as quantum dots.
Several techniques have been developed to grow or deposit semiconductor quantum dots in glass matrices. Nanocrystals of both I-VII and II-VI semiconductors have been grown in alu inoborosilicate glasses using the diffusive precipitation method described above. II-VI semiconductor quantum dots have been prepared using a variety of sol-gel glass fabrication methods as well as radiofrequency (rf) sputtering methods. II-VI semiconductor quantum dots have been deposited into porous Vycor™ (Corning, Inc) glass using precipitation reactions as well as metalloorganic chemical vapor depositions (MOCVD or CVD) methods, III-V semiconductor quantum dots have also been prepared in porous Vycor™ glass using several CVD techniques.
Previous studies of semiconductor quantum dots have predominantly focused on the optical properties, and, in particular, the nonlinear optical properties of the quantum dots. The materials processing issues have concerned the purity (stoichiometry) of the quantum dots, the crystal size and distribution, and the crystallinity. Luminescence from semiconductor-doped glasses, such as commercially available cadmium sulfide/selenide glasses, has been measured at room temperature. The luminescence appears as a narrow feature near the band edge, attributed to direct recombination, and a broad, less intense red-shifted band attributed by various authors to shallow surface related traps or defects. The luminescent features were found to be dependent on the stoichiometry of the semiconductor. Exciton and biexciton luminescence from CuCl quantum dots has been observed at low temperatures (T < 108K) and lasing due to the biexciton to exciton transition has been reported, also at 77 K.
There have been no successful prior efforts to develop activated nanocrystalline phosphors within a glass matrix, followed by appropriate heat treatment.
Summary of the Invention
It is an object of the present invention to form a transparent composite of phosphors distributed in a glass matrix.
It is another object of the present invention to provide mechanically and chemically stable phosphors.
It is a further object of the present invention to form a glass matrix doped with inorganic, luminescent nanocrystals.
These and other objects are achieved by doping a glass with inorganic nanocrystals including an activator for the nanocrystals. Typically, fabrication is accomplished by deposition of the activator and nanocrystalline semiconductor particles into a porous glass matrix.
Brief Description of the Drawings
A more complete appreciation of the invention will be readily obtained by reference to the following Description of the Preferred Embodiments and the accompanying drawings, wherein:
Fig. 1 shows the thermoluminescence signal as a function of copper sulfate concentration for a sample made according to the procedures of Example 1, but with varying concentrations of copper sulfate in the copper sulfate doping solution. The solid line shows the fluorescence excitation, while the dotted curve shows the fluorescence emission. Fig. 2 shows the thermoluminescence signal as a function of zinc nitrate concentration for a sample made according to Example 1, but with varying concentrations of zinc nitrate in the zinc nitrate doping solution. Fig. 3 shows the effect of ZnS concentration on the positions of the thermoluminescence glow peaks. Curve (a) shows the typical thermoluminescence observed at low concentrations (corresponding to 1 g/100 ml zinc nitrate in the doping solution) of copper activated (1 mg Cu/ml doping solution) ZnS nanocrystals in Vycor™ glass, while curve (b) shows the growth of a higher luminescent glow peak in a higher concentration (corresponding to 10 g/100 ml zinc nitrate in the doping solution) of copper activated (1 mg Cu/ml doping solution) ZnS nanocrystals in Vycor™ glass. Fig. 4 shows the excitation and emission spectra of a copper activated ZnS/Vycor™ glass composite phosphor made according to Example 1.
Fig. 5 shows the excitation and emission curve of a europium activated KCl/Vycor™ glass composite phosphor made according to Example 2.
Description of the Preferred Embodiments
The nanocrystalline inorganic solid/glass composite phosphors are fabricated by deposition of the inorganic solid and the activators within a porous glass matrix. The deposition can be accomplished using known chemical methods for doping glasses, such as, for example, precipitation from a liquid phase solution, or CVD. Often, the most convenient method will be precipitation from a liquid phase solution. The exact deposition process used and the parameters employed for deposition are not critical, provided that the deposited materials are nanocrystalline and the glass retains its porosity. Generally, the size of the deposited crystals is controlled by the pore size of the glass into which the crystals are deposited. The pores restrict the growth of the deposited crystals so that the deposited crystals have a diameter smaller than that of the pore in which they precipitate. However, the pores in a porous glass are in reality tortuous channels, sometimes interconnected, which behave like pores. Thus, if the concentration of the dopants within the glass becomes too great for the average effective pore size, the nanocrystals will grow through the channels, interconnect, and develop into large crystals that reduce the transparency of the glass.
Following the deposition of the inorganic solid and activators, a thermal heat treatment may be used to promote diffusion of the activators in the nanocrystals and to control the nature and quality of the crystalline phase. This heat treatment is performed at a temperature sufficient to substantially enhance diffusion of the activators. Typically, the activation temperature is also selected to partially, or perhaps even fully, consolidate the porous glass. If desired, the porous glass can be activated at a temperature below that needed to consolidate the glass. The activation temperature, however, should not be so high as to liquify the glass. For 7930 Vycor™ glass (Corning, Inc.), an activation temperature of typically from about 800 to about 1100°C may be used. The activation temperature must be below the melting temperature of the glass. Annealing, i.e., accompanied by at least partial consolidation of the glass (collapsing of at least some of the pores), requires temperatures above the T of the glass. The time for activation may be varied depending upon what, if any, degree of consolidation is required. While the order in which the components are mixed is not critical, all components of the glass, must be present during the activation step. Suitable porous glasses are amorphous matrices with densely packed, tortuous, nanometer-sized, interconnecting pores or channels. The exact chemical compositon is not critical. One example of such a glass is porous Vycor™ (Corning, Inc.). Vycor™ glass is a 96% silica glass obtained by heat treating a borosilicate glass to separate the boron and silicate phases and then subjecting the heat treated glass to an acid etch, thereby removing most of the boron phase and leaving the porous 96% silica glass. The Vycor™ glass can be obtained in a wide variety of sizes or shapes, including sheets, rods, tubes, and irregular shapes. Suitable porous glass hosts can also be prepared using well-known sol-gel glass technology. These glasses are prepared by the acid catalyzed or base catalyzed hydrolysis of metallic esters or alkoxides. Single component or multiple component glasses can be prepared and include, for example, silicate, titanate, germanate and zirconate glasses. The pore size, distribution of pore sizes and the density of the pores in the sol-gel glass can be controlled by the hydrolysis conditions and by the details of the drying procedure. The porous sol-gel glasses may also be manufactured in a wide variety of shapes and sizes as well as in thin films. Porous glass matrices that may be made by the sol-gel process include pure Si02, pure A1203 (alumina glass) , pure Ti02 and mixtures thereof in varying proportions to provide glasses with varying properties.
In the starting glasses to be doped with nanocrystalline semiconductor particles (nanocrystals) and at least one activator therefor, the pores typically average about 10 to about 100 A in diameter, more often about 40 to about 75 A in diameter and most often about 40 to about 50 A in diameter. Vycor glass™ (Corning 7930) has an average pore size of about 40 A diameter. Average pore sizes of less than 40 Angstrom diameter can be obtained using sol-gel derived glasses. Average pore sizes of less than 10 A diameter are not practical because it is difficult to diffuse solutions into the pores. Average pore sizes that are larger than 100 A in diameter may be too large to assure nanocrystal formation, depending on the concentration of the activator and semiconductor employed. The optical quality of glasses prepared from larger pore sizes is diminished. Additionally, the size distribution of the particles should be selected to maintain the transparency of the glass to its own luminescent emissions. To this end, the activator should preferably not form particles having diameters greater than about 100 A. Particles having a diameter of greater than 100 A may reduce the transparency of the glass matrix, and thus their presence within the glass should be minimized. A pore density of 25 to 30 volume percent is ideal because it allows for the formation of isolated and separated nanocrystalline structures. If the void volume is too high, the semiconductor crystallites may be too close together and merge to form particles larger than nanocrystals. Lower pore densities simply reduce the amount of semiconductor material that can be introduced to the glass. This situation may be desirable for certain applications such as doped fiber-optic cables. The nanocrystalline nature of the semiconductor particles in the material of the present invention is critical. Because of the small size of nanocrystals, glass doped therewith maintains its transparency. If the nanocrystals are sufficiently small (below about 80 A, with a narrow size distribution so that few, if any particles are more than 120 A) they may become quantum-confined. The effects of this quantum confinement are favorable in many circumstances, although quantum-confined semiconductor particles are not required to obtain many benefits of the present invention. The selection of suitable inorganic solid phosphor materials to be deposited in porous glass in an effort to fabricate nanocrystalline phosphor/glass composites is guided by previous knowledge about the most useful and efficient bulk phosphors. There have been literally thousands of different types of phosphors manufactured using many combinations of inorganic solids and activators. Some of the most useful phosphors are sulfides of zinc or alkaline earths such as calcium, magnesium and strontium, activated with transition metal or rare earth ions. Activated ZnS phosphors have found wide utility in a variety of applications including cathodoluminescence, radioluminescence, electro- luminescence, and IR sensitivity. Different activators and/or co-activators have been identified and their relative concentrations optimized for the desired application. For example, useful ZnS phosphors have been manufactured using activators and co- activators (when required) selected from the following: rare earth ions, silver, copper, lead, chloride, and manganese ions. This list is by no means complete. Sufficient activator or (activator/co-activator) should be employed in the glass to provide an activator concentration effective to luminescently activate the semiconductor nanocrystals, i.e., render the nanocrystalline semiconductor particles capable of emitting light in the visible or infrared range in response to electronic excitation at an appropriate wavelength.
The concentrations and identities of the dopants result in different physical and optical properties of the nanocrystalline semiconductor doped glass. For example, copper activated zinc sulfide glasses display the following trends: increasing the concentration of copper sulfate in the doping solution from zero to approximately 0.1 gram in 100 cubic centimeters of water shows an increase in thermoluminescence with increasing copper concentration.
As the concentration of copper is increased further, the thermoluminescence intensity decreases (Fig. 1) . high concentrations of ZnS lead to a decrease in the thermoluminescence emission from the glass (Fig. 2) . Intermediate concentrations of ZnS lead to thermoluminescent glow peaks at higher temperatures (Fig
3).
These tendencies may be characteristic of all doped glass compositions according to the present invention. At low concentrations, increasing dopant levels increase the number of luminescent crystals, thus increasing the overall luminescence. As the concentration of the activator and/or semiconductor becomes too high, the crystals grow too large and the glass loses transparency and luminescence. At intermediate concentration of semiconductors, the luminescent nanocrystalline semiconductors particles may communicate with each other, slightly changing their electronic energy levels and characteristic spectra. Also, to maintain the transparency of the glass to its own fluorescence, the number of activator particles having a particle diameter greater than about 100 A should be minimized in the glass. It may even be desirable to avoid the formation of any activator particles having a diameter of greater than about lOoA. Possibly, but not necessarily, the activator may substitute into the crystal lattice of the nanocrystalline semiconductor particles. However, activation might be the result of proximity effects between the activator and the nanocrystalline semiconductor particles.
The activated nanocrystalline inorganic solid phosphors of this invention may be manufactured, for example, from type II-VI semiconductors, of which ZnS is an example, type III-V semiconductors, of which gallium arsenide is an example, type IV-IV semiconductors, of which silicon is an example, alkali halides, of which potassium chloride is an example, or alkaline earth sulfides, of which calcium sulfide is an example. The activator and/or co-activator ions can be chosen from the rare earth metals, of which europium is an example, or the transition metals, of which manganese is an example. Co- activators also often include halogen ions, of which chloride is an example. The use of europium as an activator results in a mixed blue and red luminescence.
Doped glasses according to the present invention can exhibit cathodoluminescence, electroluminescence, thermoluminescence, radioluminescence or sensitized luminescence. The emission of light after excitation can be immediate or delayed (energy trapping) . The exact type of luminescence observed will depend, in a characteristic way, upon the semiconductor and activator used, as well as the concentration of those materials within the glass. The type of luminescence observed depends on the excitation conditions. The chemistry of the phosphor may be manipulated and predicted to enhance a particular type of luminescence.
The following is a generalized exemplary procedure for making a doped glass according to the present invention. The purpose of this generalized procedure is illustrative only. Although the doping method illustrated is precipitation from solution, it should be understood that other doping methods, dopants and porous glasses may be used.
In a typical doping procedure, a piece of porous glass, such as porous Vycor™ glass, is immersed in an aqueous solution of a water soluble metal salt such as zinc nitrate. The solution is allowed to diffuse completely throughout the porous glass. The metal salt solution concentration can range between zero and the solubility limit of the salt (1.8 grams per cubic centimeter of water for zinc nitrate) . If a metal sulfide dopant, such as zinc sulfide, is desired it may be formed in situ , for example, by the addition of an aqueous solution of thioacetamide to the solution of the water-soluble salt. The thioacetamide/metal salt solution reaction proceeds for a period of time ranging from one hour to several days, depending on the temperature of the solution. A lower temperature (about 25'C to about 50βC) results in a slower reaction and assures a uniform distribution of metal sulfide throughout the porous glass piece. An alternative method for producing a metal sulfide is to expose the metal doped glass piece to hydrogen sulfide (H2S) gas for a period of approximately one hour. The H2S gas diffuses quickly throughout the porous glass and reacts with the deposited metal salt. The porous glass, containing the desired dopant is next immersed in an aqueous solution of metal salt activator, such as copper sulfate or europium chloride. The concentration of the metal salt activator can range between zero and the solubility limit of the salt (approximately 0.4 grams per cubic centimeter for copper sulfate, although no enhancement beyond about 0.2 g ml is observed in the case of copper sulfate) . This solution is allowed to diffuse throughout the porous glass, typically at about room temperature. The glass is then dried slowly, over a period of one hour, to prevent cracking of the glass.
The temperature is raised slowly (several hours) to approximately 300 degrees centigrade and then the temperature is increased more rapidly (one hour) to typically no greater than about 1100"C - 1150'C. The glass is maintained at high temperature for a period of three to 24 hours to fully activate the glass phosphor. The glass is cooled to room temperature over a period of one to three hours. The resulting glass is highly luminescent when exposed to radiation wavelengths that overlap the absorption band of the doped, activated glass. For ZnS activated with copper, exposure to ultraviolet wavelengths of less than 300 nm, results in an intense blue-green luminescence.
Having described the invention, the following examples are given to illustrate specific applications of the invention including the best mode now known to perform the invention.
These specific examples are not intended to limit the scope of the invention described in this application.
EXAMPLES
Example l - Zinc sulfide/copper doping
0.1 g of zinc nitrate hexahydrate were dissolved in 100 ml distilled water. To the resulting solution were added 1 cc concentrated nitric acid. 1 g of porous Corning 7930 Vycor™ glass were then added to the acidified solution, in which it was allowed to remain for 1 to 2 hours to allow complete diffusion of the zinc nitrate solution throughout the glass. The glass was then removed from the solution and dried.
A thioacetamide solution was prepared by dissolving 1.0 g thioacetamide in 100 ml distilled water, adding 1 ml concentrated nitric acid. The thioacetamide solution was then placed in a constant temperature bath set to 30'C. The dried zinc-loaded porous glass was then placed into the sulfide solution and allowed to react therewith for at least 10 hours to form nanocrystalline ZnS. The porous glass sample was then removed from solution and dried.
0.01 g copper sulfate was dissolved in 100 ml water. The zinc sulfide-containing glass sample was then placed in the copper sulfate solution and allowed to remain there for 1 to 2 hours to allow complete diffusion of the copper sulfate solution throughout the porous glass. The copper doped zinc sulfide glass sample was then removed from the copper sulfate solution and dried.
The dried zinc sulfide/copper-doped porous glass was then placed in an oven at room temperature. The oven temperature was then increased at a rate of about l'C/minute up to a temperature of 300*C. Over the course of an next hour, the temperature of the oven was then raised to 1150*C. The sample was baked at 1150°C for at least 3 hours and then allowed to cool to room temperature (Cooling may occur either by shutting off the oven and allowing the sample to cool within, or by removing the sample from the oven) . The absorption spectrum of the ZnS phosphor glass exhibited a maximum at approximately 260 nm, with a broad tail extending to approximately 320 nm. This absorption feature was characteristic of excitonic absorption within ZnS nanocrystallites (quantum dots) . The location of the absorption peak reflected the blue shift of the exciton energy due to quantum confinement of the excitons. The width of the absorption feature reflected the size distribution of the quantum dots in the glass composite. After excitation of the nanocrystalline phosphor by the UV light, transfer of the energy to the copper ion activators occurs. Emission occurs from the excited copper ions. The emission is characterized by a broad band centered at approximately 500 nm, similar to that from a bulk copper activated ZnS phosphor. The quantum efficiency of the emission is also similar to that of the bulk phosphor. The temporal decay of the emission is faster than that of the bulk phosphor emission. Fig. 4 shows the emission and fluorescence excitation spectra of a sample of the copper activated ZnS quantum dot phosphor composite. The solid curve was obtained by scanning the optical excitation source from 240 nm to 350 nm and monitoring the total emission. The heavy dashed curve is the emission curve obtained by exciting the sample at 266 nm. An elemental analysis of the sample indicated that the individual concentrations of zinc sulfide and copper were less than 5 ppm.
Example 2 - KC1 activated with europium ions, manufactured in porous Vycor glass
The procedure used in Example 1 was used, except that the glass was directly doped using a solution of 1 g KC1 in 100 ml of water followed by doping with 1 g EuCl solution in 100 ml of water. No sulfides were used. The absorption spectrum of the KC1 phosphor glass exhibited a maximum at approximately 240 nm, with a broad tail extending to approximately 300 nm. This absorption feature was characteristic of absorption by europium ions within the crystal lattice of the alkali halide. The location and width of the absorption peak reflect the nature and the influence of the crystalline host environment seen by the europium ions. After excitation of the nanocrystalline phosphor by the UV light, emission occurs from the excited europium ions. The emission is characterized by a broad band centered at approximately 450 nm due to emission from Eu*2 ions, in addition to a narrow peak at 615 nm due to Eu43 emission. The emission and fluorescence excitation spectra are shown in Fig. 5. The heavy solid curve was obtained by scanning the optical excitation source from 224 nm to 350 nm and monitoring the total emission. The light solid curve is the emission spectrum obtained by exciting the sample at 266 nm.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings.
It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

ClaimsWhat is claimed is:
1. A luminescent glass comprising: a glass matrix doped with nanocrystalline semiconductor particles; a metal activator, within said glass matrix, for said nanocrystalline semiconductor particles, said metal activator being present in a concentration effective to luminescently activate said nanocrystalline semiconductor particles, said glass being transparent to its luminescent emissions.
2. The luminescent glass of claim l, wherein said glass emits light in the visible or infrared spectrum immediately after absorption of radiation.
3. The luminescent glass of claim 1, wherein said glass, upon absorption of radiation, forms trapped electrons, and emits light in the visible or infrared spectrum after upon detrapping of said trapped electron.
4. The luminescent glass of claim 3, wherein said glass detraps said electron upon heating.
5. The luminescent glass of claim 3, wherein said glass detraps said trapped electrons upon exposure to infrared radiation.
6. The luminescent glass of claim 1, wherein said nanocrystalline semiconductor particles are selected from the group consisting of II-VI and III-V semiconductors.
7. The luminescent glass of claim 6, wherein said nanocrystalline semiconductor particles are selected from the group consisting of ZnS and GaP, and wherein said activator is a transition metal ion, a rare earth ion, or a halide ion.
8. The luminescent glass of claim 7, wherein said activator is Cu*1 or a Cl".
9. A method of producing a luminescent glass that is transparent to its luminescent emissions, comprising the steps of: doping a porous glass matrix with nanocrystalline semiconductor particles, such that said nanocrystalline semiconductor particles in said glass have a size distribution that does not significantly reduce the transparency of the luminescent glass to its luminescent emissions; adding to said porous glass matrix an amount of a activator effective to luminescently activate said nanocrystalline semiconductor particles, such that the said activator within said glass does not significantly reduce the transparency of the luminescent glass to it luminescent emissions; activating said nanocrystalline semiconductor particles within said glass by heating said porous glass matrix having said activator and said nanocrystalline particles therein to a temperature of from about 800°C to below a temperature at which said porous glass matrix melts.
10. The method of claim 9, further comprising the step of at least partially collapsing said porous glass matrix after said doping steps.
11. The method of claim 9, wherein said porous glass matrix has an average pore size of about 10 to 100 A in diameter before said doping steps.
12. The method of claim 11, wherein said porous glass matrix has an average pore size of below about 80 A before said doping steps.
13. The method of claim 12, wherein said porous glass matrix has an average pore size of about 40 to about 80 A before said doping steps.
14. The method of claim 13, wherein said porous glass matrix has an average pore size of about 40 to about 50 A before said doping steps.
15. The method of claim 9, wherein said glass matrix is doped with said nanocrystalline semiconductor particles by precipitating said nanocrystalline semiconductor particles from a solution in which said glass matrix is immersed.
16. The method of claim 15, wherein said glass matrix is doped with said activator by precipitating said activator from a solution in which said glass matrix is immersed.
17. The method of claim 9, wherein said glass matrix is doped with said nanocrystalline semiconductor particles by chemical vapor deposition.
18. The method of claim 17, wherein said glass matrix is doped with said nanocrystalline semiconductor particles by metalloorganic chemical vapor deposition.
19. The method of claim 9, wherein said glass matrix is doped with said nanocrystalline semiconductor particles by steps comprising: immersing said porous glass matrix into a solution comprising a metal salt; converting said metal salt to a metal chalcogenide dopant by exposing said metal salt to gaseous H2S, H2Se or H2Te.
20. The method of claim 19, wherein said metal salt is a metal halide and is converted to a metal sulfide by exposure to gaseous H2S.
PCT/US1995/009119 1995-01-11 1995-07-20 Glass matrix doped with activated luminescent nanocrystalline particles WO1996021868A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CA002213477A CA2213477C (en) 1995-01-11 1995-07-20 Glass matrix doped with activated luminescent nanocrystalline particles
EP95928090A EP0871900B1 (en) 1995-01-11 1995-07-20 Glass matrix doped with activated luminescent nanocrystalline particles
AT95928090T ATE210307T1 (en) 1995-01-11 1995-07-20 GLASS MATRIX WITH NANOCRYSTALLINE PARTICLES ACTIVATED FOR LUMINESCENCE
JP52163196A JP3724807B2 (en) 1995-01-11 1995-07-20 Glass matrix doped with activated luminescent nanocrystalline particles
DE69524458T DE69524458T2 (en) 1995-01-11 1995-07-20 GLASS MATRIX WITH NANOCRISTALLINE PARTICLES ACTIVATED TO LUMINESCENCE

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08/371,306 1995-01-11
US08/371,306 US5585640A (en) 1995-01-11 1995-01-11 Glass matrix doped with activated luminescent nanocrystalline particles

Publications (1)

Publication Number Publication Date
WO1996021868A1 true WO1996021868A1 (en) 1996-07-18

Family

ID=23463421

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1995/009119 WO1996021868A1 (en) 1995-01-11 1995-07-20 Glass matrix doped with activated luminescent nanocrystalline particles

Country Status (7)

Country Link
US (1) US5585640A (en)
EP (1) EP0871900B1 (en)
JP (1) JP3724807B2 (en)
AT (1) ATE210307T1 (en)
CA (1) CA2213477C (en)
DE (1) DE69524458T2 (en)
WO (1) WO1996021868A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004007636A1 (en) * 2002-07-16 2004-01-22 Futaba Corporation Composite nanoparticle and process for producing the same
WO2004050576A1 (en) * 2002-11-29 2004-06-17 Japan Science And Technology Agency Luminescent glass
WO2011130913A1 (en) * 2010-04-22 2011-10-27 海洋王照明科技股份有限公司 Quantum dot-glass composite luminescent material and manufacturing method thereof
JP2014160863A (en) * 1998-04-01 2014-09-04 Massachusetts Institute Of Technology Prepolymer composition, method for preparing light-emitting device, and light-emitting device
KR20190048461A (en) * 2017-10-31 2019-05-09 주식회사 오리온이엔씨 quantum dot radiation detector

Families Citing this family (163)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU3894595A (en) * 1994-11-08 1996-05-31 Spectra Science Corporation Semiconductor nanocrystal display materials and display apparatus employing same
US5985353A (en) * 1994-12-01 1999-11-16 University Of Massachusetts Lowell Biomolecular synthesis of quantum dot composites
US6600175B1 (en) * 1996-03-26 2003-07-29 Advanced Technology Materials, Inc. Solid state white light emitter and display using same
US6106609A (en) * 1997-04-08 2000-08-22 The United States Of America As Represented By The Secretary Of The Navy Formation of nanocrystalline semiconductor particles within a bicontinuous cubic phase
US5850064A (en) * 1997-04-11 1998-12-15 Starfire Electronics Development & Marketing, Ltd. Method for photolytic liquid phase synthesis of silicon and germanium nanocrystalline materials
US5811822A (en) * 1997-04-29 1998-09-22 The United States Of America As Represented By The Secretary Of The Navy Optically transparent, optically stimulable glass composites for radiation dosimetry
US6322901B1 (en) 1997-11-13 2001-11-27 Massachusetts Institute Of Technology Highly luminescent color-selective nano-crystalline materials
US6607829B1 (en) * 1997-11-13 2003-08-19 Massachusetts Institute Of Technology Tellurium-containing nanocrystalline materials
US5990479A (en) 1997-11-25 1999-11-23 Regents Of The University Of California Organo Luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes
US6699723B1 (en) 1997-11-25 2004-03-02 The Regents Of The University Of California Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes
US6207392B1 (en) 1997-11-25 2001-03-27 The Regents Of The University Of California Semiconductor nanocrystal probes for biological applications and process for making and using such probes
US6145342A (en) * 1998-01-30 2000-11-14 The United States Of America As Represented By The Secretary Of The Navy Catalyzed preparation of amorphous chalcogenides
US6140651A (en) * 1998-02-18 2000-10-31 The United States Of America As Represented By The Secretary Of The Navy Optically stimulated, fast neutron sensor and dosimeter and fiber-optic coupled fast neutron remote sensor and dosimeter
US6087666A (en) * 1998-02-18 2000-07-11 The United States Of America As Represented By The Secretary Of The Navy Optically stimulated luminescent fiber optic radiation dosimeter
US6153339A (en) * 1998-03-31 2000-11-28 The United States Of America As Represented By The Secretary Of The Navy Volume holographic data storage with doped high optical quality glass
US6139626A (en) * 1998-09-04 2000-10-31 Nec Research Institute, Inc. Three-dimensionally patterned materials and methods for manufacturing same using nanocrystals
US6306610B1 (en) 1998-09-18 2001-10-23 Massachusetts Institute Of Technology Biological applications of quantum dots
US6617583B1 (en) * 1998-09-18 2003-09-09 Massachusetts Institute Of Technology Inventory control
US6251303B1 (en) 1998-09-18 2001-06-26 Massachusetts Institute Of Technology Water-soluble fluorescent nanocrystals
US6608439B1 (en) 1998-09-22 2003-08-19 Emagin Corporation Inorganic-based color conversion matrix element for organic color display devices and method of fabrication
US6211526B1 (en) * 1998-09-30 2001-04-03 The United States Of America As Represented By The Secretary Of The Navy Marking of materials using luminescent and optically stimulable glasses
AU1717600A (en) * 1998-11-10 2000-05-29 Biocrystal Limited Methods for identification and verification
US6528234B1 (en) * 1999-03-05 2003-03-04 The United States Of America As Represented By The Secretary Of The Navy II-VI compounds as a medium for optical data storage through fast persistent high density spectral holeburning
US6514435B1 (en) * 1999-03-05 2003-02-04 The United States Of America As Represented By The Secretary Of The Navy High density and fast persistent spectral holeburning in II-VI compounds for optical data storage
US6307212B1 (en) * 1999-04-01 2001-10-23 The United States Of America As Represented By The Secretary Of The Navy High resolution imaging using optically transparent phosphors
EP1264375A2 (en) 2000-03-14 2002-12-11 Massachusetts Institute Of Technology Optical amplifiers and lasers
WO2001071354A2 (en) 2000-03-20 2001-09-27 Massachusetts Institute Of Technology Inorganic particle conjugates
US7039289B1 (en) 2000-05-19 2006-05-02 Optinetrics, Inc. Integrated optic devices and processes for the fabrication of integrated optic devices
US6881530B1 (en) * 2000-05-19 2005-04-19 Optinetrics, Inc. Thin film sol-gel derived glass
US7016589B2 (en) * 2000-05-19 2006-03-21 Optinetrics, Inc. Thermally-assisted photo-lithographic process using sol-gel derived glass and products made thereby
US6919119B2 (en) 2000-05-30 2005-07-19 The Penn State Research Foundation Electronic and opto-electronic devices fabricated from nanostructured high surface to volume ratio thin films
US7078071B2 (en) * 2000-10-05 2006-07-18 Matsumoto Yushi-Seiyaku Co., Ltd. Glass composite including dispersed rare earth iron garnet nanoparticles
US20020110180A1 (en) * 2001-02-09 2002-08-15 Barney Alfred A. Temperature-sensing composition
US7008559B2 (en) * 2001-06-06 2006-03-07 Nomadics, Inc. Manganese doped upconversion luminescence nanoparticles
US7501092B2 (en) * 2001-06-06 2009-03-10 Nomadics, Inc. Manganese doped upconversion luminescence nanoparticles
US8618595B2 (en) * 2001-07-02 2013-12-31 Merck Patent Gmbh Applications of light-emitting nanoparticles
US6918946B2 (en) * 2001-07-02 2005-07-19 Board Of Regents, The University Of Texas System Applications of light-emitting nanoparticles
US6846565B2 (en) * 2001-07-02 2005-01-25 Board Of Regents, The University Of Texas System Light-emitting nanoparticles and method of making same
US6978070B1 (en) * 2001-08-14 2005-12-20 The Programmable Matter Corporation Fiber incorporating quantum dots as programmable dopants
US7067072B2 (en) * 2001-08-17 2006-06-27 Nomadics, Inc. Nanophase luminescence particulate material
US6637571B2 (en) * 2001-08-31 2003-10-28 Reell Precision Manufacturing Corporation Input engaging clutch
AU2002326920B2 (en) * 2001-09-17 2007-09-13 Massachusetts Institute Of Technology Semiconductor nanocrystal composite
US7150910B2 (en) * 2001-11-16 2006-12-19 Massachusetts Institute Of Technology Nanocrystal structures
US6623559B2 (en) 2001-12-10 2003-09-23 Nanotek Instruments, Inc. Method for the production of semiconductor quantum particles
US20030106488A1 (en) * 2001-12-10 2003-06-12 Wen-Chiang Huang Manufacturing method for semiconductor quantum particles
US20030129311A1 (en) * 2002-01-10 2003-07-10 Wen-Chiang Huang Method of producing quantum-dot powder and film via templating by a 2-d ordered array of air bubbles in a polymer
AU2002242509A1 (en) * 2002-03-05 2003-09-16 Institut National D'optique Microporous glass waveguides doped with selected materials
US6751387B2 (en) * 2002-03-05 2004-06-15 Institut National D'optique Microporous glass waveguides doped with selected materials
CA2934970C (en) * 2002-03-29 2019-04-30 Massachusetts Institute Of Technology Light emitting device including semiconductor nanocrystals
DE10214019A1 (en) * 2002-03-30 2003-10-16 Detlef Mueller-Schulte Luminescent, spherical, non-autofluorescent silica gel particles with variable emission intensities and frequencies
US20030193032A1 (en) * 2002-04-08 2003-10-16 Eastman Kodak Company Radiation exposure indicator device
US20070189359A1 (en) * 2002-06-12 2007-08-16 Wei Chen Nanoparticle thermometry and pressure sensors
US7515333B1 (en) * 2002-06-13 2009-04-07 Nanosy's, Inc. Nanotechnology-enabled optoelectronics
EP1541656A4 (en) * 2002-06-19 2007-11-14 Nat Inst Of Advanced Ind Scien Semiconductor superfine particle phosphor and light emitting device
US7319709B2 (en) 2002-07-23 2008-01-15 Massachusetts Institute Of Technology Creating photon atoms
WO2004053929A2 (en) * 2002-08-13 2004-06-24 Massachusetts Institute Of Technology Semiconductor nanocrystal heterostructures
JP2006502232A (en) * 2002-08-15 2006-01-19 モウンギ ジー. バウエンディ Stabilized semiconductor nanocrystals
US20050126628A1 (en) * 2002-09-05 2005-06-16 Nanosys, Inc. Nanostructure and nanocomposite based compositions and photovoltaic devices
TW200425530A (en) * 2002-09-05 2004-11-16 Nanosys Inc Nanostructure and nanocomposite based compositions and photovoltaic devices
EP2399970A3 (en) * 2002-09-05 2012-04-18 Nanosys, Inc. Nanocomposites
US7229498B2 (en) * 2002-10-29 2007-06-12 Midwest Research Institute Nanostructures produced by phase-separation during growth of (III-V)1-x(IV2)x alloys
AU2002368226A1 (en) * 2002-10-29 2004-05-25 Midwest Research Institute Nanostructures produced by phase-separation during growth of (iii-v)1-x(iv2)x alloys
US7332211B1 (en) 2002-11-07 2008-02-19 Massachusetts Institute Of Technology Layered materials including nanoparticles
US7181266B2 (en) * 2003-03-04 2007-02-20 Massachusetts Institute Of Technology Materials and methods for near-infrared and infrared lymph node mapping
US20050020922A1 (en) * 2003-03-04 2005-01-27 Frangioni John V. Materials and methods for near-infrared and infrared intravascular imaging
DE10313988B4 (en) * 2003-03-27 2014-03-27 Leica Microsystems Cms Gmbh Method for testing the quality of microscopes
US7917298B1 (en) 2003-04-17 2011-03-29 Nanosys, Inc. Nanocrystal taggants
US7005679B2 (en) 2003-05-01 2006-02-28 Cree, Inc. Multiple component solid state white light
CN1863954B (en) * 2003-08-04 2013-07-31 纳米系统公司 System and process for producing nanowire composites and electronic substrates therefrom
US7229497B2 (en) * 2003-08-26 2007-06-12 Massachusetts Institute Of Technology Method of preparing nanocrystals
US8664640B2 (en) * 2003-10-06 2014-03-04 Massachusetts Institute Of Technology Non-volatile memory device including semiconductor charge-trapping material particles
US7702764B1 (en) * 2004-01-30 2010-04-20 Cisco Technology, Inc. System and method for testing network protocols
US20050179008A1 (en) * 2004-02-18 2005-08-18 Zhiguo Xiao Light-storage self-luminescent glass and the process for producing the same
US7253452B2 (en) 2004-03-08 2007-08-07 Massachusetts Institute Of Technology Blue light emitting semiconductor nanocrystal materials
US7517728B2 (en) 2004-03-31 2009-04-14 Cree, Inc. Semiconductor light emitting devices including a luminescent conversion element
EP1761955A2 (en) * 2004-06-04 2007-03-14 The Programmable Matter Corporation Layered composite film incorporating quantum dots as programmable dopants
US7229690B2 (en) * 2004-07-26 2007-06-12 Massachusetts Institute Of Technology Microspheres including nanoparticles
US7172326B2 (en) * 2004-08-19 2007-02-06 Honeywell International, Inc. Optical filter system employing a tilted reflector
US7352007B2 (en) * 2004-08-24 2008-04-01 Micron Technology, Inc. Phosphorescent nanotube memory device
US7316967B2 (en) * 2004-09-24 2008-01-08 Massachusetts Institute Of Technology Flow method and reactor for manufacturing noncrystals
US20060196375A1 (en) * 2004-10-22 2006-09-07 Seth Coe-Sullivan Method and system for transferring a patterned material
WO2007018570A2 (en) * 2004-11-03 2007-02-15 Massachusetts Institute Of Technology Absorbing film
US7649196B2 (en) 2004-11-03 2010-01-19 Massachusetts Institute Of Technology Light emitting device
WO2006073562A2 (en) * 2004-11-17 2006-07-13 Nanosys, Inc. Photoactive devices and components with enhanced efficiency
US20060107993A1 (en) * 2004-11-19 2006-05-25 General Electric Company Building element including solar energy converter
US8891575B2 (en) * 2004-11-30 2014-11-18 Massachusetts Institute Of Technology Optical feedback structures and methods of making
US8134175B2 (en) 2005-01-11 2012-03-13 Massachusetts Institute Of Technology Nanocrystals including III-V semiconductors
CN1317574C (en) * 2005-03-04 2007-05-23 浙江工业大学 Nanocrystalline quantum dot optical fiber and optical fiber amplifier
AT501990B1 (en) * 2005-06-09 2007-03-15 Swarovski & Co MARKED BODY OF TRANSPARENT MATERIAL
US20070085010A1 (en) * 2005-06-14 2007-04-19 The Regents Of The University Of California Scintillator with a matrix material body carrying nano-material scintillator media
US7361541B2 (en) * 2005-07-27 2008-04-22 Taiwan Semiconductor Manufacturing Co., Ltd. Programming optical device
TWI396814B (en) 2005-12-22 2013-05-21 克里公司 Lighting device
US7394094B2 (en) * 2005-12-29 2008-07-01 Massachusetts Institute Of Technology Semiconductor nanocrystal heterostructures
AU2007238477A1 (en) * 2006-02-17 2007-10-25 Ravenbrick, Llc Quantum dot switching device
US8941299B2 (en) * 2006-05-21 2015-01-27 Massachusetts Institute Of Technology Light emitting device including semiconductor nanocrystals
US20080234810A1 (en) * 2006-06-28 2008-09-25 Abbott Cardiovascular Systems Inc. Amorphous Glass-Coated Drug Delivery Medical Device
US8947619B2 (en) 2006-07-06 2015-02-03 Intematix Corporation Photoluminescence color display comprising quantum dots material and a wavelength selective filter that allows passage of excitation radiation and prevents passage of light generated by photoluminescence materials
US8643058B2 (en) 2006-07-31 2014-02-04 Massachusetts Institute Of Technology Electro-optical device including nanocrystals
US20080029720A1 (en) 2006-08-03 2008-02-07 Intematix Corporation LED lighting arrangement including light emitting phosphor
US7601946B2 (en) * 2006-09-12 2009-10-13 Ravenbrick, Llc Electromagnetic sensor incorporating quantum confinement structures
US20080191193A1 (en) * 2007-01-22 2008-08-14 Xuegeng Li In situ modification of group iv nanoparticles using gas phase nanoparticle reactors
WO2008092038A1 (en) 2007-01-24 2008-07-31 Ravenbrick, Llc Thermally switched optical downconverting filter
US20080192458A1 (en) 2007-02-12 2008-08-14 Intematix Corporation Light emitting diode lighting system
US8363307B2 (en) * 2007-02-28 2013-01-29 Ravenbrick, Llc Multicolor light emitting device incorporating tunable quantum confinement devices
US7936500B2 (en) * 2007-03-02 2011-05-03 Ravenbrick Llc Wavelength-specific optical switch
US7972030B2 (en) 2007-03-05 2011-07-05 Intematix Corporation Light emitting diode (LED) based lighting systems
US8203260B2 (en) 2007-04-13 2012-06-19 Intematix Corporation Color temperature tunable white light source
JP5270862B2 (en) 2007-05-15 2013-08-21 信越石英株式会社 Copper-containing silica glass, method for producing the same, and xenon flash lamp using the same
US8968438B2 (en) * 2007-07-10 2015-03-03 Innovalight, Inc. Methods and apparatus for the in situ collection of nucleated particles
US8471170B2 (en) 2007-07-10 2013-06-25 Innovalight, Inc. Methods and apparatus for the production of group IV nanoparticles in a flow-through plasma reactor
CA2970259C (en) 2007-07-11 2018-11-06 Ravenbrick, Llc Thermally switched reflective optical shutter
KR101303981B1 (en) 2007-09-19 2013-09-04 라벤브릭 엘엘씨 Low-emissivity window films and coatings incorporating nanoscale wire grids
US8783887B2 (en) 2007-10-01 2014-07-22 Intematix Corporation Color tunable light emitting device
US7915627B2 (en) 2007-10-17 2011-03-29 Intematix Corporation Light emitting device with phosphor wavelength conversion
US8169685B2 (en) 2007-12-20 2012-05-01 Ravenbrick, Llc Thermally switched absorptive window shutter
US20090217967A1 (en) * 2008-02-29 2009-09-03 International Business Machines Corporation Porous silicon quantum dot photodetector
US8740400B2 (en) 2008-03-07 2014-06-03 Intematix Corporation White light illumination system with narrow band green phosphor and multiple-wavelength excitation
US8567973B2 (en) 2008-03-07 2013-10-29 Intematix Corporation Multiple-chip excitation systems for white light emitting diodes (LEDs)
CN102066992B (en) 2008-04-23 2013-11-13 雷文布里克有限责任公司 Glare management of reflective and thermoreflective surfaces
US9116302B2 (en) 2008-06-19 2015-08-25 Ravenbrick Llc Optical metapolarizer device
US8665414B2 (en) 2008-08-20 2014-03-04 Ravenbrick Llc Methods for fabricating thermochromic filters
US20100051443A1 (en) * 2008-08-29 2010-03-04 Kwangyeol Lee Heterodimeric system for visible-light harvesting photocatalysts
US8410511B2 (en) * 2008-10-17 2013-04-02 Goldeneye, Inc. Methods for high temperature processing of epitaxial chips
US8822954B2 (en) 2008-10-23 2014-09-02 Intematix Corporation Phosphor based authentication system
DK2417481T3 (en) 2009-04-10 2017-02-06 Ravenbrick Llc THERMAL REPLACED OPTICAL FILTER INCORPORATING A GUEST HOST ARCHITECTURE
US8651692B2 (en) 2009-06-18 2014-02-18 Intematix Corporation LED based lamp and light emitting signage
EP2480816A1 (en) 2009-09-25 2012-08-01 Cree, Inc. Lighting device with low glare and high light level uniformity
US8867132B2 (en) * 2009-10-30 2014-10-21 Ravenbrick Llc Thermochromic filters and stopband filters for use with same
JP5734993B2 (en) 2009-11-17 2015-06-17 レイブンブリック,エルエルシー Temperature response switching type optical filter incorporating refractive optical structure
US8779685B2 (en) 2009-11-19 2014-07-15 Intematix Corporation High CRI white light emitting devices and drive circuitry
US8466611B2 (en) 2009-12-14 2013-06-18 Cree, Inc. Lighting device with shaped remote phosphor
US20110149548A1 (en) * 2009-12-22 2011-06-23 Intematix Corporation Light emitting diode based linear lamps
JP5529296B2 (en) * 2010-03-05 2014-06-25 ▲海▼洋王照明科技股▲ふん▼有限公司 Luminescent nanocrystalline glass used for white light LED light source and method for producing the same
JP5890390B2 (en) 2010-03-29 2016-03-22 レイブンブリック,エルエルシー Polymer-stabilized thermotropic liquid crystal device
KR101526041B1 (en) 2010-06-01 2015-06-04 라벤브릭 엘엘씨 Multifunctional building component
US8888318B2 (en) 2010-06-11 2014-11-18 Intematix Corporation LED spotlight
US8807799B2 (en) 2010-06-11 2014-08-19 Intematix Corporation LED-based lamps
US8946998B2 (en) 2010-08-09 2015-02-03 Intematix Corporation LED-based light emitting systems and devices with color compensation
WO2012047937A1 (en) 2010-10-05 2012-04-12 Intematix Corporation Solid-state light emitting devices and signage with photoluminescence wavelength conversion
US8610341B2 (en) 2010-10-05 2013-12-17 Intematix Corporation Wavelength conversion component
US8957585B2 (en) 2010-10-05 2015-02-17 Intermatix Corporation Solid-state light emitting devices with photoluminescence wavelength conversion
US9546765B2 (en) 2010-10-05 2017-01-17 Intematix Corporation Diffuser component having scattering particles
US8604678B2 (en) 2010-10-05 2013-12-10 Intematix Corporation Wavelength conversion component with a diffusing layer
US8614539B2 (en) 2010-10-05 2013-12-24 Intematix Corporation Wavelength conversion component with scattering particles
US9279894B2 (en) * 2011-02-09 2016-03-08 Lawrence Livermore National Security, Llc Systems and methods for neutron detection using scintillator nano-materials
US9004705B2 (en) 2011-04-13 2015-04-14 Intematix Corporation LED-based light sources for light emitting devices and lighting arrangements with photoluminescence wavelength conversion
US8786050B2 (en) 2011-05-04 2014-07-22 Taiwan Semiconductor Manufacturing Company, Ltd. High voltage resistor with biased-well
US8664741B2 (en) 2011-06-14 2014-03-04 Taiwan Semiconductor Manufacturing Company Ltd. High voltage resistor with pin diode isolation
US9373619B2 (en) 2011-08-01 2016-06-21 Taiwan Semiconductor Manufacturing Company, Ltd. High voltage resistor with high voltage junction termination
WO2013033608A2 (en) 2011-09-01 2013-03-07 Wil Mccarthy Thermotropic optical shutter incorporating coatable polarizers
US8992051B2 (en) 2011-10-06 2015-03-31 Intematix Corporation Solid-state lamps with improved radial emission and thermal performance
US20130088848A1 (en) 2011-10-06 2013-04-11 Intematix Corporation Solid-state lamps with improved radial emission and thermal performance
US9365766B2 (en) 2011-10-13 2016-06-14 Intematix Corporation Wavelength conversion component having photo-luminescence material embedded into a hermetic material for remote wavelength conversion
US9115868B2 (en) 2011-10-13 2015-08-25 Intematix Corporation Wavelength conversion component with improved protective characteristics for remote wavelength conversion
WO2013163573A1 (en) 2012-04-26 2013-10-31 Intematix Corporation Methods and apparatus for implementing color consistency in remote wavelength conversion
US8994056B2 (en) 2012-07-13 2015-03-31 Intematix Corporation LED-based large area display
US20140185269A1 (en) 2012-12-28 2014-07-03 Intermatix Corporation Solid-state lamps utilizing photoluminescence wavelength conversion components
US9217543B2 (en) 2013-01-28 2015-12-22 Intematix Corporation Solid-state lamps with omnidirectional emission patterns
WO2014151263A1 (en) 2013-03-15 2014-09-25 Intematix Corporation Photoluminescence wavelength conversion components
CN104241262B (en) 2013-06-14 2020-11-06 惠州科锐半导体照明有限公司 Light emitting device and display device
US9318670B2 (en) 2014-05-21 2016-04-19 Intematix Corporation Materials for photoluminescence wavelength converted solid-state light emitting devices and arrangements
EP3274765A4 (en) 2015-03-23 2018-10-17 Intematix Corporation Photoluminescence color display
DE102015212915A1 (en) * 2015-07-09 2017-01-12 E.G.O. Elektro-Gerätebau GmbH Hob and method for generating a light on a hob

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2902605A (en) * 1953-08-25 1959-09-01 Wallack Stanley Dosimeter
US5446286A (en) * 1994-08-11 1995-08-29 Bhargava; Rameshwar N. Ultra-fast detectors using doped nanocrystal insulators

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0622439A1 (en) * 1993-04-20 1994-11-02 Koninklijke Philips Electronics N.V. Quantum sized activator doped semiconductor particles

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2902605A (en) * 1953-08-25 1959-09-01 Wallack Stanley Dosimeter
US5446286A (en) * 1994-08-11 1995-08-29 Bhargava; Rameshwar N. Ultra-fast detectors using doped nanocrystal insulators

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
J. APPL. PHYS., Vol. 61, No. 12, issued 15 June 1987, N.F. BORELLI et al., "Quantum Confinement Effects of Semiconducting Microcrystallites in Glass", pages 5399-5409. *
SUPERLATTICES AND MICROSTRUCTURES, Vol. 4, No. 3, issued 1988, JOHN C. LUONG, "Semiconductor Microcrystallites in Porous Glass and Their Applications in Optics", pages 385-390. *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014160863A (en) * 1998-04-01 2014-09-04 Massachusetts Institute Of Technology Prepolymer composition, method for preparing light-emitting device, and light-emitting device
WO2004007636A1 (en) * 2002-07-16 2004-01-22 Futaba Corporation Composite nanoparticle and process for producing the same
WO2004050576A1 (en) * 2002-11-29 2004-06-17 Japan Science And Technology Agency Luminescent glass
EP1566367A1 (en) * 2002-11-29 2005-08-24 Japan Science and Technology Agency Luminescent glass
EP1566367A4 (en) * 2002-11-29 2009-03-04 Japan Science & Tech Agency Luminescent glass
US7758774B2 (en) 2002-11-29 2010-07-20 Japan Science And Technology Agency Luminescent glass
US7938551B2 (en) 2002-11-29 2011-05-10 Japan Science And Technology Agency Luminescent glass
WO2011130913A1 (en) * 2010-04-22 2011-10-27 海洋王照明科技股份有限公司 Quantum dot-glass composite luminescent material and manufacturing method thereof
EP2562146A1 (en) * 2010-04-22 2013-02-27 Ocean's King Lighting Science&Technology Co., Ltd. Quantum dot-glass composite luminescent material and manufacturing method thereof
JP2013525243A (en) * 2010-04-22 2013-06-20 オーシャンズ キング ライティング サイエンスアンドテクノロジー カンパニー リミテッド Quantum dot / glass composite light emitting material and method for producing the same
EP2562146A4 (en) * 2010-04-22 2013-11-06 Oceans King Lighting Science Quantum dot-glass composite luminescent material and manufacturing method thereof
CN102770386A (en) * 2010-04-22 2012-11-07 海洋王照明科技股份有限公司 Quantum dot-glass composite luminescent material and manufacturing method thereof
KR20190048461A (en) * 2017-10-31 2019-05-09 주식회사 오리온이엔씨 quantum dot radiation detector
KR102044454B1 (en) * 2017-10-31 2019-11-14 주식회사 오리온이엔씨 quantum dot radiation detector

Also Published As

Publication number Publication date
JP3724807B2 (en) 2005-12-07
JPH11502610A (en) 1999-03-02
ATE210307T1 (en) 2001-12-15
CA2213477A1 (en) 1996-07-18
DE69524458T2 (en) 2002-08-01
EP0871900B1 (en) 2001-12-05
US5585640A (en) 1996-12-17
EP0871900A1 (en) 1998-10-21
DE69524458D1 (en) 2002-01-17
EP0871900A4 (en) 1999-06-30
CA2213477C (en) 2005-03-29

Similar Documents

Publication Publication Date Title
EP0871900B1 (en) Glass matrix doped with activated luminescent nanocrystalline particles
Hao et al. Optical and luminescent properties of undoped and rare-earth-doped Ga2O3 thin films deposited by spray pyrolysis
Rao The preparation and thermoluminescence of alkaline earth sulphide phosphors
US4992302A (en) Process for making photoluminescent materials
EP0394530B1 (en) High efficiency photoluminescent material for optical upconversion and a process for making the same
Ren et al. Water triggered interfacial synthesis of highly luminescent CsPbX 3: Mn 2+ quantum dots from nonluminescent quantum dots
Hasabeldaim et al. Structural, optical and photoluminescence properties of Eu doped ZnO thin films prepared by spin coating
US6241911B1 (en) Oxide based phosphors and processes therefor
US4839092A (en) Photoluminescent materials for outputting orange light
US4812660A (en) Photoluminescent materials for outputting yellow-green light
US4806772A (en) Infrared sensing device outputting orange light and a process for making the same
US5965192A (en) Processes for oxide based phosphors
US4842960A (en) High efficiency photoluminescent material for optical upconversion
US4822520A (en) Photoluminescent materials for outputting blue-green light
Gil-Rostra et al. Thin film electroluminescent device based on magnetron sputtered Tb doped ZnGa2O4 layers
US4812659A (en) Infrared sensing device outputting blue-green light
Khare et al. Optical properties of rare earth doped SrS phosphor: a review
EP0338368B1 (en) Thin film photoluminescent articles and method of making the same
US4879186A (en) Photoluminescent materials for outputting reddish-orange light and a process for making the same
US6169357B1 (en) Electron field-emission display cell device having opening depth defined by etch stop
Lou et al. Luminescence studies of BaAl2O4 films doped with Tm, Tb, and Eu
US6015326A (en) Fabrication process for electron field-emission display
US5006366A (en) Photoluminescent material for outputting orange light with reduced phosphorescence after charging and a process for making same
US4103173A (en) Fluorescent screen
US6071633A (en) Oxide based phosphors and processes therefor

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA HU JP KR PL

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref country code: JP

Ref document number: 1996 521631

Kind code of ref document: A

Format of ref document f/p: F

ENP Entry into the national phase

Ref document number: 2213477

Country of ref document: CA

Ref country code: CA

Ref document number: 2213477

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 1995928090

Country of ref document: EP

122 Ep: pct application non-entry in european phase
122 Ep: pct application non-entry in european phase
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWP Wipo information: published in national office

Ref document number: 1995928090

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1995928090

Country of ref document: EP