CA1090455A - Solar cell and method for the manufacture thereof - Google Patents
Solar cell and method for the manufacture thereofInfo
- Publication number
- CA1090455A CA1090455A CA285,904A CA285904A CA1090455A CA 1090455 A CA1090455 A CA 1090455A CA 285904 A CA285904 A CA 285904A CA 1090455 A CA1090455 A CA 1090455A
- Authority
- CA
- Canada
- Prior art keywords
- whiskers
- substrate
- doping
- semiconductor
- solar cell
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 238000000034 method Methods 0.000 title claims description 22
- 239000000758 substrate Substances 0.000 claims abstract description 33
- 239000004065 semiconductor Substances 0.000 claims abstract description 32
- 239000013078 crystal Substances 0.000 claims abstract description 15
- 239000000463 material Substances 0.000 claims description 32
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 15
- 150000001875 compounds Chemical class 0.000 claims description 15
- 229910052710 silicon Inorganic materials 0.000 claims description 15
- 239000010703 silicon Substances 0.000 claims description 15
- 239000003795 chemical substances by application Substances 0.000 claims description 13
- 238000009792 diffusion process Methods 0.000 claims description 10
- 230000006872 improvement Effects 0.000 claims description 7
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical group O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 7
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 claims description 5
- 239000004020 conductor Substances 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 3
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 claims description 3
- 229910003437 indium oxide Inorganic materials 0.000 claims description 3
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 238000004544 sputter deposition Methods 0.000 claims description 3
- 229910002058 ternary alloy Inorganic materials 0.000 claims description 3
- 229910001887 tin oxide Inorganic materials 0.000 claims description 3
- 238000007740 vapor deposition Methods 0.000 claims description 3
- 238000007733 ion plating Methods 0.000 claims description 2
- 229910000410 antimony oxide Inorganic materials 0.000 claims 1
- 230000005855 radiation Effects 0.000 description 8
- 239000002800 charge carrier Substances 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 4
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- WUPHOULIZUERAE-UHFFFAOYSA-N 3-(oxolan-2-yl)propanoic acid Chemical compound OC(=O)CCC1CCCO1 WUPHOULIZUERAE-UHFFFAOYSA-N 0.000 description 3
- MARUHZGHZWCEQU-UHFFFAOYSA-N 5-phenyl-2h-tetrazole Chemical compound C1=CC=CC=C1C1=NNN=N1 MARUHZGHZWCEQU-UHFFFAOYSA-N 0.000 description 3
- 229910005540 GaP Inorganic materials 0.000 description 3
- 229910052980 cadmium sulfide Inorganic materials 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- GPXJNWSHGFTCBW-UHFFFAOYSA-N Indium phosphide Chemical compound [In]#P GPXJNWSHGFTCBW-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910052787 antimony Inorganic materials 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 229910052793 cadmium Inorganic materials 0.000 description 2
- 150000002259 gallium compounds Chemical class 0.000 description 2
- 230000035784 germination Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000006862 quantum yield reaction Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910017115 AlSb Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- LVQULNGDVIKLPK-UHFFFAOYSA-N aluminium antimonide Chemical compound [Sb]#[Al] LVQULNGDVIKLPK-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- -1 compounds indium phosphide Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- HZXMRANICFIONG-UHFFFAOYSA-N gallium phosphide Chemical compound [Ga]#P HZXMRANICFIONG-UHFFFAOYSA-N 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000007792 gaseous phase Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000012780 transparent material Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
- C30B11/04—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method adding crystallising materials or reactants forming it in situ to the melt
- C30B11/08—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method adding crystallising materials or reactants forming it in situ to the melt every component of the crystal composition being added during the crystallisation
- C30B11/12—Vaporous components, e.g. vapour-liquid-solid-growth
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
- H01L31/0352—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
- H01L31/035272—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions characterised by at least one potential jump barrier or surface barrier
- H01L31/035281—Shape of the body
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/547—Monocrystalline silicon PV cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12528—Semiconductor component
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12674—Ge- or Si-base component
Abstract
ABSTRACT OF THE DISCLOSURE
A solar cell with semiconductor consisting of single crystal semiconductor whiskers which are grown on a substrate surface permitting relatively inexpensive manufacture and high efficiency of the solar cell is disclosed.
A solar cell with semiconductor consisting of single crystal semiconductor whiskers which are grown on a substrate surface permitting relatively inexpensive manufacture and high efficiency of the solar cell is disclosed.
Description
lOgO45S : ~
The invention relates to solar cells in general and more particul-arly to an improved solar cell and method of manufacture therefor.
Solar cells having zones of opposite doping forming a p-n junction in their semiconductor body which are each provided with an electrode are known. ~ -Solar cells are electronic semiconductor components, by means of which sunlight can be converted into electric energy. The semiconductor body can consist, for instance, of silicon or a III-V compound such as gallium ar-senide and is provided on its front side facing the radiation with a p-n junc-tion of large area by means of diffusion. Planar metal contacts on the back side and thin metallic contact strips on the front side are used as electrodes for collecting the current generated in such a semiconductor crystal. At the p-n junction a diffusion voltage, the magnitude of which is tetermined by the impurity concentration in the adjacent zones is generated at ther~al equilibrium.
It forms an internal field over the space charge zone of the boundary layer.
If lîght quanta with sufficiently large energy now enter such a semiconductor,-~ -additional pairs of charge carriers are produced on both sides of the p-n junc- -tion in excess over the thermal equilibrium. The charge carriers produced ;~
then move toward the p-n junction and are separated in the electric field of the latter. This separation results in a reduction of the internal potential.
2Q The difference from the potential of the thermal equilibrium appears as a photo voltage, the equalization of the charges then taking place in an external load circuit connected to the semiconductor crystal, giving off electric energy. -As is well known, solar cells are designed with a view to~ard per- -mitting as many photons as possible to penetrate into the semiconductor and so -that the number of charge carriers reaching the p-n junction as well as the available power become as large as possible. The zone of the semiconductor body facing the light, which is in general of the n-conduction type and deter- - ~
iorates less than a p-conduction zone, is therefore chosen as thîn as possible,`- ~ -so that a high percentage of the light absorbed in the very thin semiconductor 3Q layer contributes to the energy conversîon. The conversion length is then ''~"`", '.
l~O~S5 approximately equal to the diffusion length. In addition, the layer resistance of this n-conduction zone is chosen small lest the efficiency of the solar cell be reduced by an excessively large series or internal resistance. In addition, it is advantageous to choose a starting material with a resistivity of between 1 and 10 ohm-cm. The cells made of such materials are degraded but little if exposed to corpuscular radiation.
Furthermore, the life of the minority carriers and, therefore, the diffusion length is sufficiently large so that a consider-able portion of the light quanta which are absorbed only further inside on the side of the p-n junction facing away from the direction of the incident light, generates charge carriers which still can reach the p-n junction.
A large portion of the light incident on the semi-conductor surface of a solar cell is reflected; in the case of a plane silicon surface, this portion can be as much as 32%.
The known solar cells are therefore generally provided with a layer of suitable thickness of a material with a matched index of refraction, in order to limit the reflection losses to a negligible amount (Federal Republic of Germany Offenlengungss-chrift 1 934 751 of Siemens AG, laid open January 14, 1971).
Solar cells generally contain a plane semiconductor body some 100 ~m thick, for instance, 350 ~m thick, of single crystal, p-conduction silicon, into the top side of which a thin n-conduction zone with a small thickness of, for instance, 0.3 ~m is diffused. The manufacture of such silicon sheets, however, is very elaborate and expensive, so that the production of energy with such cells is substantially more expensive than other energy production methods.
It is therefore an object of the present invention to provide a solar cell which can be produced less expensively and the efficiency of which is further increased over that of the l~)gO4SS
known solar cells.
This problem is solved for a solar cell of the type mentioned at the outset by the provision that its semiconductor body consists of semiconductor whiskers grown on a substrate surface.
Thus, in accordance with one broad aspect of the invention, there is provided, in a solar cell having a semi-conductor body with zones of opposite doping forming a p-n junction and each zone provided with an electrode, the improve-ment comprising the semiconductor body consisting of single crystal semiconductor whiskers grown on a substrate surface. -. . : .
In accordance with another aspect of the invention ~ -~
there is provided a method for manufacturing solar cells com-prising growing semiconductor whiskers on a substrate using the vapor liquid solid (VLS) method, said method further includ-ing first doping the grown but still undoped whiskers with one .
of a p or n doping material and subsequently thereto doping the ;~
region close to the surface up to a depth which approximately corresponds to the diffusion length with the other of a p or n doping material. ;~
A whisker is understood here to be a filamentary crystal of high strength, several ~m in diameter and with ~ -lengths of up to several cm. As a rule, its structure is that ~-of a single crystal with a nearly ideal lattice.
A substrate is understood here to be a material which at least favors the growth or germination of whiskers and on the surface of which the whiskers can be grown in a reaction chamber. Although the substrate may be present in particle form, e.g., as dust, whisker fragments or other materials, pre-ferred substrates are heat resistant materials such as aluminum oxide or silicate, which are commonly used in sheet or tube form. Details on whisker growing methods may be found, for 1~9(~455 instance, in the book "Whisker Technology", New York 1970, edited by A.P. Levitt, published by Wiley-Inter-Science.
The advantages of the solar cell according to the present invention are in particular that the whiskers provided for this cell are single crystals and therefore make possible a high efficiency of the cell. The large surface to volume ratio of the whiskers, which leads to a p-n junction in the cell of particularLy large surface, results in a large increase of the quantum yield as compared to a plane surface. In addition, such whiskers can absorb the radiation almost without reflection. An antireflection layer as in the known solar cells is therefore not necessary. Since the absorption depth `~;~can be chosen approximately equal to the diffusion length of the charge carrier pairs in the whisker material, savings of material results while the quantum yield and the efficiency are increased. In addition, the solar cells according to the present invention can be produced by applying all the processes required therefore in series. Such production is relatively cost effective.
In the known solar cells, finger contacts, which leave an area as large as possible free for the passage of light, are used as electrodes on the light side of the semi-conductor body (United States Patent No. 3,772,770 of Arndt et ~-al, issued November 20, 1973). It is advantageous not to use -such contacts for the solar cell according to the present ~-invention, as it is not possible to cover the entire surface of all whiskers with these contacts. Therefore in accordance with a further embodiment of the solar cell according to the present ; -invention, the surfaces of the semiconductor whiskers are ~;
coated with a layer of a transparent, electrically ~';''~.' ~ ''.
-3a-~ " ' ;, . - :- :
- . . . : :
~9o~ss conductive material. Suitable materials are, for instance, tin oxide doped with antimony SnO2(Sb) or indium oxide doped with tin In2O3(Sn). Their trans-parency in the visible range of the spectrum is better than 80%. Since no antireflection layers are required with the whiskers, the application of such transparent layers is possible. The whiskers can be coated with these layers at least on most of the surface, so that a correspondingly large percentage of the charge carriers getting to the surface is collected.
These light transparent, electrically conducting layers, which serve as one of the two electrodes of the solar cell, can be applied advantageously by cathode sputtering, vapor deposition or ion plating to the surfaces of the semiconductor whiskers With these techniques, a relatively uniform layer thickness can be achieved on the entire whisker surface, and particularly so at the tips of the whiskers. ~ ;
According to a further embodiment of the solar cell of the present ~ :,, ~. ,- .
invention, the substrate and/or a carrier to which the substrate is applied, ~
: , can advantageously consist of a material of high electric conductivity. The substrate or the carrier can then serve at the same time as the electrode on the side of the solar cell facing away from the radiation.
It is further of advantage if, for solar cells with silicon semi~
conductor whiskers, polycrystalline silicon is provided as the substrate. On this relatively inexpensive material, particularly, perfect single-crystal `~ -~
whiskers can be grown.
For growing the semiconductor whiskers of a solar cell according to the present invention, the so-called vapor-liquid solid mechanism ~VLS ~ `
mechanism) can advantageously be used, which is known from the journal "Transactions of the Metallurgîcal Society of AIME", vol. 233, June 1965, pages 1053 to 1064 According to this crystal growing mechanism, the material to be crystallized is absorbed in a predetermined amount of a metal which is placed on the substrate and in which the material to be crystallizsd is soluble,and which is called the agent. At a suîtable predetermined temperature, an 1~9~455 alloy is formed during the precipitation with the material to be crystallized, which is saturated upon further precipitation of this material. Thus, super-saturation and precipitation of the material on the substrate comes about and, finally, growth of the whiskers with the liquid agent at the tips of the former.The crystal growth which occurs is heavily anisotropic, i.e., it takes place nearly in a direction perpendicular to the substrate surface, since the absorption Gf the crystallizing material or its components takes place preferentially at the free surface of the liquid phase, while the precipitation ;~ -~
from the liquid metal phase occurs only at the boundary surface between the drops and the substrate.
With the method mentioned, a large area can advantageously be pro-vided with whiskers. The manufacture of the solar cells according to ~he ~ -present invention is accordingly cost effective.
Por making solar cells according to the present invention with ~-semiconductor whiskers of a III-V compound or a ternary alloy with such a com- -pound, it can be advantageous to use the first partner of this alloy or com-pound as the agent. Such compounds may be in particular the gallium compounds gallium arsenide ~aAs), gallium phosphide ~GaP) or the ternary compound gallium arsenide phosphide (Ga(Asl xPX)) as well as the compounds indium phosphide 2Q (InP), cadmium telluride (CdTe), aluminum antimonide (AlSb) and cadmium sulfide (CdS). With crystals of these materials, solar cells having efficiencies which are higher than, for instance, the efficiency of the solar cells with silicon semiconductor whiskers can be manufactured, since the band gap of these materials is closer to the band gap of 1.5 eV, which is optimum for solar cells, than the band gap of silicon. Since the first compound partner of these compounds can -act at the same time as the agent, the danger is small that foreign substances which lead to a reduction of the efficiency of the solar cells, will be in-corporated into the whisker crystals.
The single figure is a schematic presentation of a whisker solar cell according to the present inven~ion.
lQ90455 The solar cell, which is shown in a partial cross section in the figure, comprises a substrate surface 2, on which stand a multiplicity of single crystal semiconductor whiskers. In the figure, only eight whiskers 4 of equal size, arranged parallel side by side, are shown. Their heights and their diameters, which are, for instance, in the order of 100 ~m or several hundred ~m, may be different, however. In addition, the whiskers may have a cross section which varies over their height.
With respect to the incident sunlight radiation which is indicated by individual arrows 5, the solar cell is oriented so that its whiskers 4 are directed substantially against the direction of incidence of this radiation.
Thus, the radiation can be adsorbed almost completely by the whiskers with this -structure.
Due to the spectral composition of the s~nlight, the optimum band ~
gap of the whisker material used for the solar cell, as measured in electron ~ -volts (eV~, should be about 1.5 eV. The band gap of silicon is approximately 1.1 eV, so that the output voltage produced by a silicon solar cell is corres~
pondingly small and the efficiency of the energy conversion of such a cell is in the order of about 11%. One will therefore attempt to use materials with larger band gaps for solar cells~ Such materîals are, for instance, certain semiconductive III-V compounds or also ternary alloys with such compounds.
Thus, gallium arsenide, for instance, has a band gap of approximately 1.4 eV.
The whiskers 4 are advantageously grown on the substrate 2 in ac-cordance with the known VLS mechanism. The corresponding method is applicabile, for instance, to Si and particularly also to GaAs, GaP and Ga~Asl xPX). While in the case of silicon, Au, Pt, Pd, Ni, Cu or Ag can be used as the agent, the Ga itself advantageously serves as the agent in the case of the gallium com-pounds mentioned. Other highly effective compounds with large band gaps are InP, CdTe, AlSb and CdS, to which the YLS method is likewise applicable. With these compounds also a foreign material agent is not necessary, so that the first compound partne~ can serve as the agent, i.e., In, Cd, Al or Cd, res-1(~90455 pectively. Also Ge whiskers can be grown by the known method, likewise using Au as the agent.
In the known VLS method, the growth conditions for the whiskers in a reaction chamber provided for this purpose are heavily dependent on the tem-perature of the substrate. A similarly strong influence is also exerted by the vapor deposition rate or the degree of supersaturation of the vapor in the reaction chamber. The whisker diameter depends substantially on the particle size of the agent material and the temperature. Thus, increasing tempera- ~ -tures lead to larger whisker diameters due to better wetting of the substrate surface. The agent material can be applied, for instance, through masks to specific points on the substrate surface or may also simply be vapor deposited on the substrate. During the vapor desposition or the heating of the substrate, small droplets then form on the substrate su~face. The size of the droplets depends, for instance, on the layer thickness of the vapor deposited material.
With the known method, whisker densities of, say, 104 cm2 to 106/
cm can be obtained. This corresponds to a mean whisker width of 100 to 10 ~m to the arrangement is rectangular.
Any substance favoring whisker growth or whisker germination can be used as material for the substrate 2. Thus, single or also polycrystalline silicon substrate can be provided, for instance, for growing silicon whiskers.
As is shown in the figure, such electrically nonconducting substrates are ad-vantageously placed on an electrically conducting carrier body 6, which acts at the same time as an electrode. Advantageously, electrically conducting metal strips can also be provided as the substrate body and at the same time as the electrode. In the case of silicon whisker growing, such a strip can consist of carbon-free steel, for instance.
Doping of the whiskers g~own by the VLS method can be carried out in accordance with known techniques. Thus, p-doping of silicon whiskers can take place after they are grown or, in some cases, also while they are being grown, with boron or alumlnum. Subsequently the surface of this now p-con-~90455 s ducting whisker is given a doping of the opposite type for forming an n-conduct-ing border zone 8, for instance, by diffusing phosphorus from the gaseous phase into the surface up to a depth which approximately corresponds to the diffusion length. The remaining p-conducting layers of the whiskers are designated 9 in the figure. The p-n junction formed between the n- and p-conduction zones 8 and 9 is indicated in the figure by a dashed line 10. The position in depth ~
of this p-n junction 10 can be adjusted in a manner known per se by the dif- ;~ ~-fusion conditions, e.g., the diffusion time, the diffusion temperature or the -~ gas flow.
Although n-doping of the boTder zone 8 near the surface and p-doping in the underlying zone 9 has been assumed, the doping of the two zones can just . . .
as well be arranged in the opposite manner, as is also known per se.
Por developing an electrode facing the incident light for the solar cell according to the present invention, the surface of the whiskers 4 is coated with a layer 12 of light transparent material, which is at the same time electrically conductive. Advantageously, materials which absorb only a small fraction of the energy of the incident radiation are used. Such matertals are, for instance, tin oxide doped with antimony SnO2(Sb) or also indium oxide doped with tin, In203(Sn). Suitable techniques for applying those layers are, for instance, the so-called cathode sputtering method, which is described in the journal "Vakuumtechnik"J vol. 24J Hg. 1975J no. 1J pages 1 to 11. The ;layers can also be vapor deposited or applied by means o~ ion plat~ngJ where the materials are vapor depositedJ the vapor is partially ionized by a plasma discharge and the ionized portion in the vapor is precipitated electrostatically -~
with the neutral vapor.
~'` ', ,~'
The invention relates to solar cells in general and more particul-arly to an improved solar cell and method of manufacture therefor.
Solar cells having zones of opposite doping forming a p-n junction in their semiconductor body which are each provided with an electrode are known. ~ -Solar cells are electronic semiconductor components, by means of which sunlight can be converted into electric energy. The semiconductor body can consist, for instance, of silicon or a III-V compound such as gallium ar-senide and is provided on its front side facing the radiation with a p-n junc-tion of large area by means of diffusion. Planar metal contacts on the back side and thin metallic contact strips on the front side are used as electrodes for collecting the current generated in such a semiconductor crystal. At the p-n junction a diffusion voltage, the magnitude of which is tetermined by the impurity concentration in the adjacent zones is generated at ther~al equilibrium.
It forms an internal field over the space charge zone of the boundary layer.
If lîght quanta with sufficiently large energy now enter such a semiconductor,-~ -additional pairs of charge carriers are produced on both sides of the p-n junc- -tion in excess over the thermal equilibrium. The charge carriers produced ;~
then move toward the p-n junction and are separated in the electric field of the latter. This separation results in a reduction of the internal potential.
2Q The difference from the potential of the thermal equilibrium appears as a photo voltage, the equalization of the charges then taking place in an external load circuit connected to the semiconductor crystal, giving off electric energy. -As is well known, solar cells are designed with a view to~ard per- -mitting as many photons as possible to penetrate into the semiconductor and so -that the number of charge carriers reaching the p-n junction as well as the available power become as large as possible. The zone of the semiconductor body facing the light, which is in general of the n-conduction type and deter- - ~
iorates less than a p-conduction zone, is therefore chosen as thîn as possible,`- ~ -so that a high percentage of the light absorbed in the very thin semiconductor 3Q layer contributes to the energy conversîon. The conversion length is then ''~"`", '.
l~O~S5 approximately equal to the diffusion length. In addition, the layer resistance of this n-conduction zone is chosen small lest the efficiency of the solar cell be reduced by an excessively large series or internal resistance. In addition, it is advantageous to choose a starting material with a resistivity of between 1 and 10 ohm-cm. The cells made of such materials are degraded but little if exposed to corpuscular radiation.
Furthermore, the life of the minority carriers and, therefore, the diffusion length is sufficiently large so that a consider-able portion of the light quanta which are absorbed only further inside on the side of the p-n junction facing away from the direction of the incident light, generates charge carriers which still can reach the p-n junction.
A large portion of the light incident on the semi-conductor surface of a solar cell is reflected; in the case of a plane silicon surface, this portion can be as much as 32%.
The known solar cells are therefore generally provided with a layer of suitable thickness of a material with a matched index of refraction, in order to limit the reflection losses to a negligible amount (Federal Republic of Germany Offenlengungss-chrift 1 934 751 of Siemens AG, laid open January 14, 1971).
Solar cells generally contain a plane semiconductor body some 100 ~m thick, for instance, 350 ~m thick, of single crystal, p-conduction silicon, into the top side of which a thin n-conduction zone with a small thickness of, for instance, 0.3 ~m is diffused. The manufacture of such silicon sheets, however, is very elaborate and expensive, so that the production of energy with such cells is substantially more expensive than other energy production methods.
It is therefore an object of the present invention to provide a solar cell which can be produced less expensively and the efficiency of which is further increased over that of the l~)gO4SS
known solar cells.
This problem is solved for a solar cell of the type mentioned at the outset by the provision that its semiconductor body consists of semiconductor whiskers grown on a substrate surface.
Thus, in accordance with one broad aspect of the invention, there is provided, in a solar cell having a semi-conductor body with zones of opposite doping forming a p-n junction and each zone provided with an electrode, the improve-ment comprising the semiconductor body consisting of single crystal semiconductor whiskers grown on a substrate surface. -. . : .
In accordance with another aspect of the invention ~ -~
there is provided a method for manufacturing solar cells com-prising growing semiconductor whiskers on a substrate using the vapor liquid solid (VLS) method, said method further includ-ing first doping the grown but still undoped whiskers with one .
of a p or n doping material and subsequently thereto doping the ;~
region close to the surface up to a depth which approximately corresponds to the diffusion length with the other of a p or n doping material. ;~
A whisker is understood here to be a filamentary crystal of high strength, several ~m in diameter and with ~ -lengths of up to several cm. As a rule, its structure is that ~-of a single crystal with a nearly ideal lattice.
A substrate is understood here to be a material which at least favors the growth or germination of whiskers and on the surface of which the whiskers can be grown in a reaction chamber. Although the substrate may be present in particle form, e.g., as dust, whisker fragments or other materials, pre-ferred substrates are heat resistant materials such as aluminum oxide or silicate, which are commonly used in sheet or tube form. Details on whisker growing methods may be found, for 1~9(~455 instance, in the book "Whisker Technology", New York 1970, edited by A.P. Levitt, published by Wiley-Inter-Science.
The advantages of the solar cell according to the present invention are in particular that the whiskers provided for this cell are single crystals and therefore make possible a high efficiency of the cell. The large surface to volume ratio of the whiskers, which leads to a p-n junction in the cell of particularLy large surface, results in a large increase of the quantum yield as compared to a plane surface. In addition, such whiskers can absorb the radiation almost without reflection. An antireflection layer as in the known solar cells is therefore not necessary. Since the absorption depth `~;~can be chosen approximately equal to the diffusion length of the charge carrier pairs in the whisker material, savings of material results while the quantum yield and the efficiency are increased. In addition, the solar cells according to the present invention can be produced by applying all the processes required therefore in series. Such production is relatively cost effective.
In the known solar cells, finger contacts, which leave an area as large as possible free for the passage of light, are used as electrodes on the light side of the semi-conductor body (United States Patent No. 3,772,770 of Arndt et ~-al, issued November 20, 1973). It is advantageous not to use -such contacts for the solar cell according to the present ~-invention, as it is not possible to cover the entire surface of all whiskers with these contacts. Therefore in accordance with a further embodiment of the solar cell according to the present ; -invention, the surfaces of the semiconductor whiskers are ~;
coated with a layer of a transparent, electrically ~';''~.' ~ ''.
-3a-~ " ' ;, . - :- :
- . . . : :
~9o~ss conductive material. Suitable materials are, for instance, tin oxide doped with antimony SnO2(Sb) or indium oxide doped with tin In2O3(Sn). Their trans-parency in the visible range of the spectrum is better than 80%. Since no antireflection layers are required with the whiskers, the application of such transparent layers is possible. The whiskers can be coated with these layers at least on most of the surface, so that a correspondingly large percentage of the charge carriers getting to the surface is collected.
These light transparent, electrically conducting layers, which serve as one of the two electrodes of the solar cell, can be applied advantageously by cathode sputtering, vapor deposition or ion plating to the surfaces of the semiconductor whiskers With these techniques, a relatively uniform layer thickness can be achieved on the entire whisker surface, and particularly so at the tips of the whiskers. ~ ;
According to a further embodiment of the solar cell of the present ~ :,, ~. ,- .
invention, the substrate and/or a carrier to which the substrate is applied, ~
: , can advantageously consist of a material of high electric conductivity. The substrate or the carrier can then serve at the same time as the electrode on the side of the solar cell facing away from the radiation.
It is further of advantage if, for solar cells with silicon semi~
conductor whiskers, polycrystalline silicon is provided as the substrate. On this relatively inexpensive material, particularly, perfect single-crystal `~ -~
whiskers can be grown.
For growing the semiconductor whiskers of a solar cell according to the present invention, the so-called vapor-liquid solid mechanism ~VLS ~ `
mechanism) can advantageously be used, which is known from the journal "Transactions of the Metallurgîcal Society of AIME", vol. 233, June 1965, pages 1053 to 1064 According to this crystal growing mechanism, the material to be crystallized is absorbed in a predetermined amount of a metal which is placed on the substrate and in which the material to be crystallizsd is soluble,and which is called the agent. At a suîtable predetermined temperature, an 1~9~455 alloy is formed during the precipitation with the material to be crystallized, which is saturated upon further precipitation of this material. Thus, super-saturation and precipitation of the material on the substrate comes about and, finally, growth of the whiskers with the liquid agent at the tips of the former.The crystal growth which occurs is heavily anisotropic, i.e., it takes place nearly in a direction perpendicular to the substrate surface, since the absorption Gf the crystallizing material or its components takes place preferentially at the free surface of the liquid phase, while the precipitation ;~ -~
from the liquid metal phase occurs only at the boundary surface between the drops and the substrate.
With the method mentioned, a large area can advantageously be pro-vided with whiskers. The manufacture of the solar cells according to ~he ~ -present invention is accordingly cost effective.
Por making solar cells according to the present invention with ~-semiconductor whiskers of a III-V compound or a ternary alloy with such a com- -pound, it can be advantageous to use the first partner of this alloy or com-pound as the agent. Such compounds may be in particular the gallium compounds gallium arsenide ~aAs), gallium phosphide ~GaP) or the ternary compound gallium arsenide phosphide (Ga(Asl xPX)) as well as the compounds indium phosphide 2Q (InP), cadmium telluride (CdTe), aluminum antimonide (AlSb) and cadmium sulfide (CdS). With crystals of these materials, solar cells having efficiencies which are higher than, for instance, the efficiency of the solar cells with silicon semiconductor whiskers can be manufactured, since the band gap of these materials is closer to the band gap of 1.5 eV, which is optimum for solar cells, than the band gap of silicon. Since the first compound partner of these compounds can -act at the same time as the agent, the danger is small that foreign substances which lead to a reduction of the efficiency of the solar cells, will be in-corporated into the whisker crystals.
The single figure is a schematic presentation of a whisker solar cell according to the present inven~ion.
lQ90455 The solar cell, which is shown in a partial cross section in the figure, comprises a substrate surface 2, on which stand a multiplicity of single crystal semiconductor whiskers. In the figure, only eight whiskers 4 of equal size, arranged parallel side by side, are shown. Their heights and their diameters, which are, for instance, in the order of 100 ~m or several hundred ~m, may be different, however. In addition, the whiskers may have a cross section which varies over their height.
With respect to the incident sunlight radiation which is indicated by individual arrows 5, the solar cell is oriented so that its whiskers 4 are directed substantially against the direction of incidence of this radiation.
Thus, the radiation can be adsorbed almost completely by the whiskers with this -structure.
Due to the spectral composition of the s~nlight, the optimum band ~
gap of the whisker material used for the solar cell, as measured in electron ~ -volts (eV~, should be about 1.5 eV. The band gap of silicon is approximately 1.1 eV, so that the output voltage produced by a silicon solar cell is corres~
pondingly small and the efficiency of the energy conversion of such a cell is in the order of about 11%. One will therefore attempt to use materials with larger band gaps for solar cells~ Such materîals are, for instance, certain semiconductive III-V compounds or also ternary alloys with such compounds.
Thus, gallium arsenide, for instance, has a band gap of approximately 1.4 eV.
The whiskers 4 are advantageously grown on the substrate 2 in ac-cordance with the known VLS mechanism. The corresponding method is applicabile, for instance, to Si and particularly also to GaAs, GaP and Ga~Asl xPX). While in the case of silicon, Au, Pt, Pd, Ni, Cu or Ag can be used as the agent, the Ga itself advantageously serves as the agent in the case of the gallium com-pounds mentioned. Other highly effective compounds with large band gaps are InP, CdTe, AlSb and CdS, to which the YLS method is likewise applicable. With these compounds also a foreign material agent is not necessary, so that the first compound partne~ can serve as the agent, i.e., In, Cd, Al or Cd, res-1(~90455 pectively. Also Ge whiskers can be grown by the known method, likewise using Au as the agent.
In the known VLS method, the growth conditions for the whiskers in a reaction chamber provided for this purpose are heavily dependent on the tem-perature of the substrate. A similarly strong influence is also exerted by the vapor deposition rate or the degree of supersaturation of the vapor in the reaction chamber. The whisker diameter depends substantially on the particle size of the agent material and the temperature. Thus, increasing tempera- ~ -tures lead to larger whisker diameters due to better wetting of the substrate surface. The agent material can be applied, for instance, through masks to specific points on the substrate surface or may also simply be vapor deposited on the substrate. During the vapor desposition or the heating of the substrate, small droplets then form on the substrate su~face. The size of the droplets depends, for instance, on the layer thickness of the vapor deposited material.
With the known method, whisker densities of, say, 104 cm2 to 106/
cm can be obtained. This corresponds to a mean whisker width of 100 to 10 ~m to the arrangement is rectangular.
Any substance favoring whisker growth or whisker germination can be used as material for the substrate 2. Thus, single or also polycrystalline silicon substrate can be provided, for instance, for growing silicon whiskers.
As is shown in the figure, such electrically nonconducting substrates are ad-vantageously placed on an electrically conducting carrier body 6, which acts at the same time as an electrode. Advantageously, electrically conducting metal strips can also be provided as the substrate body and at the same time as the electrode. In the case of silicon whisker growing, such a strip can consist of carbon-free steel, for instance.
Doping of the whiskers g~own by the VLS method can be carried out in accordance with known techniques. Thus, p-doping of silicon whiskers can take place after they are grown or, in some cases, also while they are being grown, with boron or alumlnum. Subsequently the surface of this now p-con-~90455 s ducting whisker is given a doping of the opposite type for forming an n-conduct-ing border zone 8, for instance, by diffusing phosphorus from the gaseous phase into the surface up to a depth which approximately corresponds to the diffusion length. The remaining p-conducting layers of the whiskers are designated 9 in the figure. The p-n junction formed between the n- and p-conduction zones 8 and 9 is indicated in the figure by a dashed line 10. The position in depth ~
of this p-n junction 10 can be adjusted in a manner known per se by the dif- ;~ ~-fusion conditions, e.g., the diffusion time, the diffusion temperature or the -~ gas flow.
Although n-doping of the boTder zone 8 near the surface and p-doping in the underlying zone 9 has been assumed, the doping of the two zones can just . . .
as well be arranged in the opposite manner, as is also known per se.
Por developing an electrode facing the incident light for the solar cell according to the present invention, the surface of the whiskers 4 is coated with a layer 12 of light transparent material, which is at the same time electrically conductive. Advantageously, materials which absorb only a small fraction of the energy of the incident radiation are used. Such matertals are, for instance, tin oxide doped with antimony SnO2(Sb) or also indium oxide doped with tin, In203(Sn). Suitable techniques for applying those layers are, for instance, the so-called cathode sputtering method, which is described in the journal "Vakuumtechnik"J vol. 24J Hg. 1975J no. 1J pages 1 to 11. The ;layers can also be vapor deposited or applied by means o~ ion plat~ngJ where the materials are vapor depositedJ the vapor is partially ionized by a plasma discharge and the ionized portion in the vapor is precipitated electrostatically -~
with the neutral vapor.
~'` ', ,~'
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a solar cell having a semiconductory body with zones of opposite doping forming a p-n junction and each zone provided with an electrode, the improvement comprising the semi-conductor body consisting of single crystal semiconductor whiskers grown on a substrate surface.
2. The improvement according to claim 1, and further including a layer of a transparent, electrically conductive material on the surfaces of the semiconductor whiskers to form electrodes thereon.
3. The improvement according to claim 2, wherein said conductive layer is selected from the group consisting of tin oxide doped with antimony and indium oxide doped with tin.
4. The improvement according to claim 1, wherein said whiskers are silicon semiconductor whiskers, and wherein said substrate is a silicon layer applied to a carrier.
5. The improvement according to claim 1, wherein said substrate is polycrystalline silicon.
6. The improvement according to claim 1, wherein at least one of the substrate and a carrier to which the substrate is applied, consists of an electrically highly conductive material.
7. A method for manufacturing solar cells comprising growing semiconductor whiskers on a substrate using the vapor liquid solid (VLS) method, said method further including first doping the grown but still undoped whiskers with one of a p or n doping material and subsequently thereto doping the region close to the surface up to a depth which approximately corresponds to the diffusion length with the other of a p or n doping material.
8. The method according to claim 7, wherein said semiconductor whiskers are of a material selected from the group consisting of a III-V compound and a ternary alloy with the partners of a III-V compound, wherein the first partner of said material is used as an agent in growing said whiskers.
9. The method according to claim 7, and further includ-ing the step of applying electrically conducting layers on the surfaces of the semiconductory whiskers by sputtering, vapor deposition or ion plating.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2639841A DE2639841C3 (en) | 1976-09-03 | 1976-09-03 | Solar cell and process for its manufacture |
DEP2639841.4 | 1976-09-03 |
Publications (1)
Publication Number | Publication Date |
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CA1090455A true CA1090455A (en) | 1980-11-25 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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CA285,904A Expired CA1090455A (en) | 1976-09-03 | 1977-08-31 | Solar cell and method for the manufacture thereof |
Country Status (6)
Country | Link |
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US (1) | US4099986A (en) |
JP (1) | JPS5331987A (en) |
CA (1) | CA1090455A (en) |
DE (1) | DE2639841C3 (en) |
FR (1) | FR2363898A1 (en) |
GB (1) | GB1529139A (en) |
Families Citing this family (51)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4252865A (en) * | 1978-05-24 | 1981-02-24 | National Patent Development Corporation | Highly solar-energy absorbing device and method of making the same |
US4187126A (en) * | 1978-07-28 | 1980-02-05 | Conoco, Inc. | Growth-orientation of crystals by raster scanning electron beam |
JPS608574B2 (en) * | 1978-08-12 | 1985-03-04 | 大阪大学長 | Semiconductor emitter for ion source |
US4268711A (en) * | 1979-04-26 | 1981-05-19 | Optical Coating Laboratory, Inc. | Method and apparatus for forming films from vapors using a contained plasma source |
US4352948A (en) * | 1979-09-07 | 1982-10-05 | Massachusetts Institute Of Technology | High-intensity solid-state solar-cell device |
US5767559A (en) * | 1991-05-24 | 1998-06-16 | Fuji Xerox Co., Ltd. | Thin film type photoelectric conversion device |
JP2697474B2 (en) * | 1992-04-30 | 1998-01-14 | 松下電器産業株式会社 | Manufacturing method of microstructure |
JP2787550B2 (en) * | 1994-11-10 | 1998-08-20 | 仗祐 中田 | Method for producing spherical crystals |
KR100294057B1 (en) * | 1995-08-22 | 2001-09-17 | 모리시타 요이찌 | Semiconductor device comprising a silicon structure layer, method and method of manufacturing the layer and solar cell using the layer |
US6147372A (en) * | 1999-02-08 | 2000-11-14 | Taiwan Semiconductor Manufacturing Company | Layout of an image sensor for increasing photon induced current |
AUPR174800A0 (en) * | 2000-11-29 | 2000-12-21 | Australian National University, The | Semiconductor processing |
TW554388B (en) | 2001-03-30 | 2003-09-21 | Univ California | Methods of fabricating nanostructures and nanowires and devices fabricated therefrom |
US20040154656A1 (en) * | 2003-02-10 | 2004-08-12 | Science & Technology Corporation @ Unm | Nuclear radiation fueled power cells |
KR100983232B1 (en) * | 2005-03-01 | 2010-09-20 | 조지아 테크 리서치 코포레이션 | Three dimensional multi-junction photovoltaic device |
US20060207647A1 (en) * | 2005-03-16 | 2006-09-21 | General Electric Company | High efficiency inorganic nanorod-enhanced photovoltaic devices |
DE102005029162B4 (en) * | 2005-06-23 | 2012-12-27 | Wilfried von Ammon | Solar cell with a whisker structure and method for its production |
WO2008048232A2 (en) * | 2005-08-22 | 2008-04-24 | Q1 Nanosystems, Inc. | Nanostructure and photovoltaic cell implementing same |
JP5925861B2 (en) * | 2005-08-24 | 2016-05-25 | ザ トラスティーズ オブ ボストン カレッジThe Trustees Of Boston College | Apparatus and method for manipulating light using nanoscale co-metallic structures |
US20070295399A1 (en) * | 2005-12-16 | 2007-12-27 | Bp Corporation North America Inc. | Back-Contact Photovoltaic Cells |
US20070137692A1 (en) * | 2005-12-16 | 2007-06-21 | Bp Corporation North America Inc. | Back-Contact Photovoltaic Cells |
US20080008844A1 (en) * | 2006-06-05 | 2008-01-10 | Martin Bettge | Method for growing arrays of aligned nanostructures on surfaces |
US20080006319A1 (en) * | 2006-06-05 | 2008-01-10 | Martin Bettge | Photovoltaic and photosensing devices based on arrays of aligned nanostructures |
WO2007146769A2 (en) * | 2006-06-13 | 2007-12-21 | Georgia Tech Research Corporation | Nano-piezoelectronics |
JP2008028118A (en) * | 2006-07-20 | 2008-02-07 | Honda Motor Co Ltd | Manufacturing method of multijunction solar battery |
EP1892769A2 (en) * | 2006-08-25 | 2008-02-27 | General Electric Company | Single conformal junction nanowire photovoltaic devices |
US7893348B2 (en) * | 2006-08-25 | 2011-02-22 | General Electric Company | Nanowires in thin-film silicon solar cells |
US7977568B2 (en) * | 2007-01-11 | 2011-07-12 | General Electric Company | Multilayered film-nanowire composite, bifacial, and tandem solar cells |
US20090179523A1 (en) * | 2007-06-08 | 2009-07-16 | Georgia Tech Research Corporation | Self-activated nanoscale piezoelectric motion sensor |
DE102007051603A1 (en) * | 2007-10-23 | 2009-04-30 | Mannesmann Fuchs Rohr Gmbh | Solar plant for converting solar energy into electrical energy, has tubular solar cell carriers which are provided with solar active elements on circumferential surface |
JP5379811B2 (en) * | 2008-02-29 | 2013-12-25 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Photovoltaic devices using high aspect ratio nanostructures and methods for making same |
US8592675B2 (en) | 2008-02-29 | 2013-11-26 | International Business Machines Corporation | Photovoltaic devices with enhanced efficiencies using high-aspect-ratio nanostructures |
US8022601B2 (en) * | 2008-03-17 | 2011-09-20 | Georgia Tech Research Corporation | Piezoelectric-coated carbon nanotube generators |
US8143143B2 (en) | 2008-04-14 | 2012-03-27 | Bandgap Engineering Inc. | Process for fabricating nanowire arrays |
US20100326503A1 (en) * | 2008-05-08 | 2010-12-30 | Georgia Tech Research Corporation | Fiber Optic Solar Nanogenerator Cells |
US7705523B2 (en) * | 2008-05-27 | 2010-04-27 | Georgia Tech Research Corporation | Hybrid solar nanogenerator cells |
US8294141B2 (en) * | 2008-07-07 | 2012-10-23 | Georgia Tech Research Corporation | Super sensitive UV detector using polymer functionalized nanobelts |
US20100012190A1 (en) * | 2008-07-16 | 2010-01-21 | Hajime Goto | Nanowire photovoltaic cells and manufacture method thereof |
JP2010028092A (en) * | 2008-07-16 | 2010-02-04 | Honda Motor Co Ltd | Nanowire solar cell and producing method of the same |
US8211735B2 (en) * | 2009-06-08 | 2012-07-03 | International Business Machines Corporation | Nano/microwire solar cell fabricated by nano/microsphere lithography |
US9202954B2 (en) * | 2010-03-03 | 2015-12-01 | Q1 Nanosystems Corporation | Nanostructure and photovoltaic cell implementing same |
JP2012023342A (en) * | 2010-06-18 | 2012-02-02 | Semiconductor Energy Lab Co Ltd | Photoelectric conversion device and method of producing the same |
WO2011158722A1 (en) * | 2010-06-18 | 2011-12-22 | Semiconductor Energy Laboratory Co., Ltd. | Photoelectric conversion device and manufacturing method thereof |
JP5792523B2 (en) * | 2010-06-18 | 2015-10-14 | 株式会社半導体エネルギー研究所 | Method for manufacturing photoelectric conversion device |
JP2012023343A (en) * | 2010-06-18 | 2012-02-02 | Semiconductor Energy Lab Co Ltd | Photoelectric conversion device and method of producing the same |
US9076909B2 (en) * | 2010-06-18 | 2015-07-07 | Semiconductor Energy Laboratory Co., Ltd. | Photoelectric conversion device and method for manufacturing the same |
CN102054890B (en) * | 2010-10-29 | 2013-01-02 | 中国科学院半导体研究所 | Monocrystalline thin film heterojunction solar cell and preparation method thereof |
JP5920758B2 (en) * | 2011-03-02 | 2016-05-18 | 本田技研工業株式会社 | Nanowire solar cell |
US20130220406A1 (en) * | 2012-02-27 | 2013-08-29 | Sharp Kabushiki Kaisha | Vertical junction solar cell structure and method |
US9082911B2 (en) | 2013-01-28 | 2015-07-14 | Q1 Nanosystems Corporation | Three-dimensional metamaterial device with photovoltaic bristles |
US9954126B2 (en) | 2013-03-14 | 2018-04-24 | Q1 Nanosystems Corporation | Three-dimensional photovoltaic devices including cavity-containing cores and methods of manufacture |
US20140264998A1 (en) | 2013-03-14 | 2014-09-18 | Q1 Nanosystems Corporation | Methods for manufacturing three-dimensional metamaterial devices with photovoltaic bristles |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE624959A (en) * | 1961-11-20 | |||
US3233111A (en) * | 1962-05-31 | 1966-02-01 | Union Carbide Corp | Silicon whisker photocell with short response time |
US3278337A (en) * | 1962-08-24 | 1966-10-11 | Int Rectifier Corp | Device for converting radiant energy into electrical energy |
US3418170A (en) * | 1964-09-09 | 1968-12-24 | Air Force Usa | Solar cell panels from nonuniform dendrites |
US3984256A (en) * | 1975-04-25 | 1976-10-05 | Nasa | Photovoltaic cell array |
US3985579A (en) * | 1975-11-26 | 1976-10-12 | The United States Of America As Represented By The Secretary Of The Air Force | Rib and channel vertical multijunction solar cell |
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- 1976-09-03 DE DE2639841A patent/DE2639841C3/en not_active Expired
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1977
- 1977-08-23 US US05/827,026 patent/US4099986A/en not_active Expired - Lifetime
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- 1977-08-31 CA CA285,904A patent/CA1090455A/en not_active Expired
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FR2363898B1 (en) | 1980-07-11 |
GB1529139A (en) | 1978-10-18 |
JPS5331987A (en) | 1978-03-25 |
FR2363898A1 (en) | 1978-03-31 |
DE2639841B2 (en) | 1980-02-14 |
US4099986A (en) | 1978-07-11 |
DE2639841C3 (en) | 1980-10-23 |
DE2639841A1 (en) | 1978-04-20 |
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