WO2010111764A2 - Varistor-type, nanostructured semiconductor device made of conducting polymer, zinc oxide and metals - Google Patents

Varistor-type, nanostructured semiconductor device made of conducting polymer, zinc oxide and metals Download PDF

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WO2010111764A2
WO2010111764A2 PCT/BR2010/000141 BR2010000141W WO2010111764A2 WO 2010111764 A2 WO2010111764 A2 WO 2010111764A2 BR 2010000141 W BR2010000141 W BR 2010000141W WO 2010111764 A2 WO2010111764 A2 WO 2010111764A2
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semiconductor device
zinc oxide
varistor
type semiconductor
nanostructured
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PCT/BR2010/000141
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French (fr)
Portuguese (pt)
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WO2010111764A3 (en
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Walter Mendes De Azevedo
Eronides Felisberto Da Silva Junior
Jorlandio Francisco Feliz
Elder Alpes De Vasconcelos
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Universidade Federal De Pernambuco - Ufpe
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
    • H01C7/1013—Thin film varistors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
    • H01C7/105—Varistor cores
    • H01C7/108—Metal oxide
    • H01C7/112—ZnO type
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K10/00—Organic devices specially adapted for rectifying, amplifying, oscillating or switching; Organic capacitors or resistors having a potential-jump barrier or a surface barrier
    • H10K10/20—Organic diodes
    • H10K10/29—Diodes comprising organic-inorganic heterojunctions

Definitions

  • Nano-structured semiconductor device of the variant type consisting of conducting polymer and zinc oxide and metals
  • the present invention relates to a semiconductor nanometric device consisting of a conductive polymer (Polyaniline - PANI) and zinc oxide (ZnO) heterojunction, which by monitoring the doping properties of the conductive polymer and the physical dimensions of the oxide films of zinc can obtain various electronic devices with specific electrical characteristics, depending on the set of parameters it is possible with this technology to obtain a semiconductor junction of type pn with rectifying characteristics as well as to obtain a device with electrical characteristics of a Varistor whose unprecedented characteristics we are requesting privilege of invention.
  • a semiconductor nanometric device consisting of a conductive polymer (Polyaniline - PANI) and zinc oxide (ZnO) heterojunction, which by monitoring the doping properties of the conductive polymer and the physical dimensions of the oxide films of zinc can obtain various electronic devices with specific electrical characteristics, depending on the set of parameters it is possible with this technology to obtain a semiconductor junction of type pn with rectifying characteristics as well as to obtain a device with electrical characteristics of a Varistor whose unprecedented characteristics we are requesting
  • the device as shown in figures 1 and 2 is composed of a support which may be glass, plastic or any other material (1), where a thin film of a metal may be deposited on it (5), on this film is After a spin coating deposition of a polyaniline thin film with a typical thickness of 300 nm (4), zinc oxide electrodes of varying thickness and size are deposited on this film to give the desired properties (3), finally contacts. aluminum or gold metal (2) are deposited on top of these film structures.
  • the electrical characteristics of these new devices compare to the devices found in the literature with a superior feature due to the fact that it is an organic hybrid device which makes this technology cheaper and more affordable to produce in a developing country. Another important aspect is that it is possible to control the working voltages of the device as a function of the degree of doping and the thickness of the device components, so it is possible to prepare a range of devices with varying working voltages.
  • the present proposal concerns an inorganic organic hybrid system with specific electrical characteristics that depends on manufacturing parameters and which can be used as a rectifier diode or Varistor.
  • the main feature of this invention is the fact that it was possible to obtain a device with electrical response from a varistor by controlling the doping state of the conducting polymer, this unprecedented physical fact allows for the first time the development of a hybrid electronic device with these characteristics. previously only possible with doping on the inorganic substrate of ZnO.
  • ZnO is a widely studied semiconductor material for many years that has been strategically applied in various areas such as abrasives, brake linings, dental products, lubricants, pigments in UV protection paints, electronic devices, optoelectronic devices, etc.
  • ZnO is transparent in the UV - Visible region of the electromagnetic spectrum due to its direct gap of ⁇ 3.37 eV. This feature makes ZnO excellent for device development in this region of the spectrum.
  • its high excon bonding energy makes it a strong candidate for light emitting device applications, because the higher this bonding energy the greater the light emission efficiency.
  • Transparent conducting oxides commonly referred to as TCO (Transparent Conducting Oxide) have been distinguished substantially between materials in part because of their common use as transparent electrodes.
  • Many electronic devices such as photovoltaic cells, LEDs (Light Emitting Diodes) need a transparent conductive layer to improve their operating efficiency.
  • TCO is used in the form of thin films, acting as transparent electrical contacts. Consequently the electrical, optical and chemical properties of conventional TCO films consisting of doped and undoped metal oxides such as ZnO, ln 2 0 3 , Sn0 2 and CdO have been intensively studied in recent years. In order to obtain thin films for specific applications, new production techniques of these materials have been actively developed and studied in recent years.
  • TCO thin films are obtained in amorphous or polycrystalline form with resistivity of the order of 10 "3 Q.cm.
  • the most used are: sputtering, resistive thermal evaporation, Physical Vapor Deposition (PVD) Metal-Organic Chemical Vapor Deposition (MOCVD), electronically pulsed laser deposition (PLD), Spray pyrolysis, etc.
  • PVD Physical Vapor Deposition
  • MOCVD Metal-Organic Chemical Vapor Deposition
  • PLD electronically pulsed laser deposition
  • Spray pyrolysis etc.
  • the films obtained generally exhibit a transmittance of 80% or more over the wavelength range.
  • Electromagnetic spectrum and carrier concentration in the order of 10 cm “3 and high band gap energy are important properties for application to devices.
  • processes require fine control of certain variables.
  • the process variables that affect the quality of the films produced are: oxygen flow (0 2 ) inside the chamber (if the amount of O2 is excessive, the resistivity will increase and If, on the other hand, the amount of 0 2 is very small, the transmittance will be deficient), substrate temperature (allows greater adhesion of the film and may improve resistivity) and deposition rate (influence on the homogeneity of the film).
  • ZnO Because it is a wide gap semiconductor and has high exciton bonding energy, ZnO draws a lot of attention in applications such as devices. For example, a device made of wide gap material may exhibit high breaking voltage, low noise generation and may operate at high temperatures and high power. Thus the performance of electronic devices produced with this material is different in low and high electric fields.
  • Conductive organic polymers are characterized by the presence of an extended ⁇ conjugation in their main chain and specific properties such as low energies of optical transitions, low ionization potentials, high electronic affinities. Therefore, they are more easily oxidized and reduced than conventional polymers.
  • These materials are synthesized by the oxidative coupling polymerization of a monomer in solution, generally containing aromatic rings or carbon-carbon multiple bonds. The polymerization process can be chemical or electrochemical, and the conductivity level of these materials is in the range of 10 + 2 to 10 "11 S.cm " 1 , in addition these materials combine the characteristics of plastics with the electrical properties.
  • polyaniline has stood out in part because its electrical properties can be reversibly controlled by changing the oxidation state of the main chain or by protonating the nitrogen imine atoms of the polymer chain.
  • the conductive form of polyaniline exhibits excellent thermal and environmental stability.
  • the present invention relates to an original process of manufacturing nanostructured zinc oxide thin films, conductive polymers and metallic films for the development of heterojunctions with distinct electrical properties, ie rectifying diodes characterized by conducting electricity in only one of the polarizations as well as heterojunctions with properties of a Varistor, a device characterized by conducting electricity in both forward and reverse polarization. That is, they have variable resistor properties, so that as the potential difference applied to the varistor increases, its electrical resistance decreases.
  • the device consists of a sandwich-shaped structure as shown in figures 1 and 2, consisting of a support which may be plastic, glass or any other substrate that serves as a mechanical support for making the device (1) thereon.
  • a gold-plated metallic film which serves as an electrical contact (5) is deposited by thermal evaporation.
  • a nanometer polyaniline film is deposited on the surface by spin-coating technique (4), or another technique for producing nanofilms, then a zinc oxide nanometric contact through the thermal evaporation technique is deposited on this surface (3) and finally an aluminum or gold nanofilm (2) is deposited to make the second electric contact of the heterojunction as shown in figure 2 , this configuration allows the electrical characterization of devices, as shown in the results of figures 3-5.
  • Figure 3 shows the characteristic I x V curves of the AI / ZnO / PANI / Au heterojunction. For devices processed with typical 100 nm contact-shaped ZnO and doped NIBP, This electrical response is characteristic of a pn type device. with rectifying characteristics.
  • Figure 4 shows a second type of I x V characteristic curves obtained with devices processed with contact-shaped ZnO with thicknesses of 100 nm, 200 nm and 350 nm, respectively, where in (d) is shown the comparison of the curves.
  • I x V characteristics of these three devices, but in all cases the NIBP is in the unpopulated state. It is observed that in this case the device presents a characteristic electric response of a Varistor type device, that is, the device conducts in both polarizations (direct and reverse) with a rupture voltage that varies between ⁇ 40 volts depending on the manufacturing conditions.
  • Nonlinearity coefficient (a) around 15. It is observed that the curves I x V have nonlinear characteristics and present a high degree of symmetry independent of the thickness of ZnO contact used. Since one of the most important properties of a varistor is its nonlinear I x V characteristic, one realizes the potential for application of these heterojunctions with varistors. In a varistor-type device it is ideal to have a high value of nonlinearity coefficient ⁇ (coefficient that defines the nonlinearity of a varistor).
  • Figure 5 shows the comparison of I x V curves between a commercial IR varistor and two ZnO and NIBP based devices.
  • the basis of this invention is based on the fact that the polyaniline conductive polymer can be prepared in various doping states and oxidation degree.
  • the device When the polymer is in the doped state the device has characteristics of a pn junction, on the other hand when the polymer is in the semi-doped or undoped state device the heterojunction is characteristic of a Varistor device.
  • the electrical properties of conventional varistors depend not only on factors such as oxide surface stoichiometry, powder preparation methodology, temperature and calcination atmosphere, but mainly on the large specific area due to the low oxide densification.
  • the manufacturing process of conventional varistors involves high processing temperatures (around 1200 ° C), therefore precise control of high temperatures is difficult and involves also higher energy expenditure.
  • the voltage of conventional varistors is determined by the thickness of the material (usually processed in cylindrical shape) and the grain size of the material (eg ZnO), where each grain boundary behaves as a 2 to 3V microvistor.
  • V n (3V) n, where n is the average number of grain boundaries between the electrodes
  • D (n + 1) d where is the average grain size.
  • the control of the varistor voltage is made by controlling the thickness of ZnO, that is, increasing the thickness of ZnO increases the rupture voltage, identical to the varistor Conventional, however our methodology allows an extra control of the rupture voltage, besides controlling the voltage of the varistor through the thickness of ZnO it is also possible to control it by doping the polymer.
  • NIBP in its unpopulated (fully insulating) state it is possible to obtain varistors with rupture voltage up to 40 V.
  • NIBP is in the natural state (state with low conductivity) it is possible to obtain varistors with voltage of 5 V. .

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Electromagnetism (AREA)
  • Nanotechnology (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Thermistors And Varistors (AREA)

Abstract

The present invention relates to a semiconducting nanodevice comprising a heterojunction made of a conducting polymer (PANI) and zinc oxide (ZnO). Electronic devices having specific electric characteristics can be obtained by controlling the doping properties, the degree of oxidation of the conducting polymer and the physical dimensions of the zinc oxide films. This technology can be used to produce a semiconducting p-n junction having with rectifier diode characteristics, as well as a varistor-type device with controlled breakdown voltages, and having unprecedented features for which protection is sought. The device comprises a metallic film made of either gold or aluminium, a thin polyaniline film of various thicknesses and sizes, a zinc oxide film of various thickness and sizes, and finally metallic contacts made of aluminium or gold as depicted in figure 1. The electric characteristics of these new devices are improved over those of commercially available devices, since they constitute organic hybrid devices which are cheaper and easier to produce. Another important aspect is the possibility to control the breakdown voltage of the device by varying the degree of doping and the thickness of the active components.

Description

DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR CONSTITUÍDO DE POLÍMERO CONDUTOR E OXIDO DE ZINCO E METAIS  Nano-structured semiconductor device of the variant type consisting of conducting polymer and zinc oxide and metals
Refere-se a presente invenção a um dispositivo nanométrico semicondutor constituído de uma heterojunção polímero condutor (Polianilina - PANI) e oxido de zinco (ZnO), que através do monitoramento das propriedades de dopagem do polímero condutor e das dimensões físicas dos filmes de óxidos de zinco consegue-se obter vários dispositivos eletrônicos com características elétricas especificas, dependendo do conjunto de parâmetros é possível com esta tecnologia obter uma junção semicondutora do tipo p-n com características retificadoras como também obter um dispositivo com características elétricas de um Varistor cujas características inéditas estamos solicitando privilegio de invenção. O dispositivo conforme mostrado na figura 1 e 2 é composto de um suporte que pode ser vidro, plástico ou qualquer outro material (1 ), onde sobre este é depositado um filme fino de um metal podendo ser ouro (5), sobre este filme é feito uma deposição via spin coating de um filme fino de polianilina com espessura típica de 300 nm (4), sobre este filme são depositados eletrodos de oxido de zinco de espessura e tamanhos variados de modos a conferir as propriedades desejadas (3), finalmente contatos metálicos de alumínio ou ouro (2) são depositados no topo desta estruturas de filmes. As características elétricas destes novos dispositivos comparam-se aos dispositivos encontrados na literatura com uma característica superior devido ao fato de ser um dispositivo híbrido orgânico o que torna esta tecnologia mais barata e mais acessível de ser produzido em um país em desenvolvimento. Outro aspecto importante é o fato de ser possível controlar as tensões de trabalho do dispositivo em função do grau de dopagem e da espessura dos componentes dos dispositivos, sendo assim é possível preparar uma gama de dispositivos com variadas tensões de trabalho.  The present invention relates to a semiconductor nanometric device consisting of a conductive polymer (Polyaniline - PANI) and zinc oxide (ZnO) heterojunction, which by monitoring the doping properties of the conductive polymer and the physical dimensions of the oxide films of zinc can obtain various electronic devices with specific electrical characteristics, depending on the set of parameters it is possible with this technology to obtain a semiconductor junction of type pn with rectifying characteristics as well as to obtain a device with electrical characteristics of a Varistor whose unprecedented characteristics we are requesting privilege of invention. The device as shown in figures 1 and 2 is composed of a support which may be glass, plastic or any other material (1), where a thin film of a metal may be deposited on it (5), on this film is After a spin coating deposition of a polyaniline thin film with a typical thickness of 300 nm (4), zinc oxide electrodes of varying thickness and size are deposited on this film to give the desired properties (3), finally contacts. aluminum or gold metal (2) are deposited on top of these film structures. The electrical characteristics of these new devices compare to the devices found in the literature with a superior feature due to the fact that it is an organic hybrid device which makes this technology cheaper and more affordable to produce in a developing country. Another important aspect is that it is possible to control the working voltages of the device as a function of the degree of doping and the thickness of the device components, so it is possible to prepare a range of devices with varying working voltages.
A presente proposta refere-se a um sistema híbrido orgânico inorgânico com características elétricas especificas que depende de parâmetros de fabricação e que pode ser utilizado como um diodo retificador ou Varistor. A característica principal desta invenção é o fato de que foi possível obter um dispositivo com resposta elétrica de um varistor controlando-se o estado de dopagem do polímero condutor, este fato físico inédito permite pela primeira vês o desenvolvimento de um dispositivo eletrônico híbrido com estas características que antes só era possível com dopagem no substrato inorgânico do ZnO.  The present proposal concerns an inorganic organic hybrid system with specific electrical characteristics that depends on manufacturing parameters and which can be used as a rectifier diode or Varistor. The main feature of this invention is the fact that it was possible to obtain a device with electrical response from a varistor by controlling the doping state of the conducting polymer, this unprecedented physical fact allows for the first time the development of a hybrid electronic device with these characteristics. previously only possible with doping on the inorganic substrate of ZnO.
O ZnO é um material semicondutor amplamente estudado há diversos anos que têm sido estrategicamente aplicado em diversas áreas tais como: abrasivos, revestimentos de freios, produtos odontológicos, lubrificantes, pigmentos em tintas para proteção UV, dispositivos eletrônicos, dispositivos optoeletrônicos, etc. O ZnO é transparente na região UV - Visível do espectro eletromagnético devido a seu gap direto de ~ 3.37 eV. Esta característica torna o ZnO excelente para o desenvolvimento de dispositivos nesta região do espectro. Por outro lado a sua alta energia de ligação de exciton faz dele um forte candidato para aplicações em dispositivos emissores de luz, pois quanto maior for essa energia de ligação maior será a eficiência de emissão de luz. É importante mencionar também que sobre condições específicas de deposição e/ou crescimento e usando técnicas de processamento apropriadas, é possível, utilizando-se o ZnO como material precursor, a obtenção de diversos tipos de heteroestruturas, tais como: nanoanéis, nanohélices, nanomolas, nonocintas, nanoarcos, nanofios, nanoestrelas. Trabalhos recentes mostram que estas nanoestruturas, devido a sua grande razão volume/área, são ideais para o desenvolvimento de sensores de gás e sensores químicos. Estas características torna ZnO um material interessante do ponto de vista de aplicações avançadas. ZnO is a widely studied semiconductor material for many years that has been strategically applied in various areas such as abrasives, brake linings, dental products, lubricants, pigments in UV protection paints, electronic devices, optoelectronic devices, etc. ZnO is transparent in the UV - Visible region of the electromagnetic spectrum due to its direct gap of ~ 3.37 eV. This feature makes ZnO excellent for device development in this region of the spectrum. On the other hand, its high excon bonding energy makes it a strong candidate for light emitting device applications, because the higher this bonding energy the greater the light emission efficiency. It is also important to mention that under specific deposition and / or growth conditions and using appropriate processing techniques, it is possible, using ZnO as a precursor material, to obtain various types of heterostructures, such as: nano rings, nano helices, nanomoles, nonocinta, nanoarchs, nanowires, nanostrars. Recent work shows that these nanostructures, due to their large volume / area ratio, are ideal for the development of gas sensors and chemical sensors. These features make ZnO an interesting material from the point of view of advanced applications.
Os óxidos condutores transparentes, comumente designados peia sigla inglesa TCO (Transparent Conducting Oxide), têm se distinguido substancialmente entre os materiais em parte por causa de seu uso corriqueiro como eletrodos transparentes. Muitos dispositivos eletrônicos, como células fotovoltaicas, LEDs (Díodos Emissores de Luz) necessitam de uma camada condutora transparente para melhorar a eficiência no seu funcionamento. Neste caso, o TCO é utilizado em forma de filmes finos, funcionando como contatos elétricos transparentes. Consequentemente as propriedades elétricas, óticas e químicas de filmes de TCO convencionais consistindo de óxidos metálicos dopados e não dopados, tais como, ZnO, ln203, Sn02 e CdO estão sendo intensamente estudadas nos últimos anos. Com o objetivo de se obter filmes finos para aplicações específicas, novas técnicas de produção destes materiais têm sido ativamente desenvolvidas e estudadas nos últimos anos. Dependendo da técnica utilizada filmes finos de TCO são obtidos na forma amorfa ou policristalina com resistividade da ordem de 10"3 Q.cm. Dentre várias técnicas de deposição, as mais utilizadas são: sputtering, evaporação térmica resistiva, Physical Vapor Deposition (PVD) Metal-Organic Chemical Vapour Deposition (MOCVD), pulsed laser deposition (PLD), eletroquimicamente, Spray pyrolysis, entre outras. Os filmes obtidos exibem, em geral, uma transmitância igual ou superior a 80% no intervalo de comprimento de onda Transparent conducting oxides, commonly referred to as TCO (Transparent Conducting Oxide), have been distinguished substantially between materials in part because of their common use as transparent electrodes. Many electronic devices, such as photovoltaic cells, LEDs (Light Emitting Diodes) need a transparent conductive layer to improve their operating efficiency. In this case, TCO is used in the form of thin films, acting as transparent electrical contacts. Consequently the electrical, optical and chemical properties of conventional TCO films consisting of doped and undoped metal oxides such as ZnO, ln 2 0 3 , Sn0 2 and CdO have been intensively studied in recent years. In order to obtain thin films for specific applications, new production techniques of these materials have been actively developed and studied in recent years. Depending on the technique used TCO thin films are obtained in amorphous or polycrystalline form with resistivity of the order of 10 "3 Q.cm. Among the several deposition techniques, the most used are: sputtering, resistive thermal evaporation, Physical Vapor Deposition (PVD) Metal-Organic Chemical Vapor Deposition (MOCVD), electronically pulsed laser deposition (PLD), Spray pyrolysis, etc. The films obtained generally exhibit a transmittance of 80% or more over the wavelength range.
20 visível do espectro eletromagnético e concentração de portadores da ordem de 10 cm"3 e alta energia de band gap. Para maximizar a transmitância e a resistividade dos filmes finos, que são propriedades importantes para aplicação em dispositivos os processos requerem um controle fino de certas variáveis. No caso das técnicas de vaporação térmica resistiva e sputtering, por exemplo, as variáveis de processo que afetam a qualidade dos filmes produzidos são: fluxo de oxigénio (02) dentro da câmara (se a quantidade de O2 for excessiva, aumentará a resistividade e se por outro lado à quantidade de 02 for ínfima a transmitância será deficiente), temperatura do substrato (permite maior adesão do filme e pode melhorar a resistividade) e taxa de deposição (influência na homogeneidade do filme). Electromagnetic spectrum and carrier concentration in the order of 10 cm "3 and high band gap energy. To maximize transmittance and resistivity of the Thin films, which are important properties for application to devices, processes require fine control of certain variables. In the case of resistive thermal vaporization and sputtering techniques, for example, the process variables that affect the quality of the films produced are: oxygen flow (0 2 ) inside the chamber (if the amount of O2 is excessive, the resistivity will increase and If, on the other hand, the amount of 0 2 is very small, the transmittance will be deficient), substrate temperature (allows greater adhesion of the film and may improve resistivity) and deposition rate (influence on the homogeneity of the film).
Devido ao fato de ser um semicondutor de gap largo e ter alta energia de ligação de exciton, o ZnO desperta muita atenção em aplicações como dispositivos. Por exemplo, um dispositivo produzido com material de gap largo pode exibir alta tensão de ruptura, baixo geração de ruído e pode operar em altas temperaturas e alta potência. Dessa forma o desempenho de dispositivos eletrônicos produzidos com este material é diferente em baixos e altos campos elétricos. Por outro lado, as propriedades elétricas de filmes de ZnO, na maioria das vezes, são difíceis de se quantificar, pois elas dependem fortemente da metodologia de síntese e/ou deposição e /ou crescimento, consequentemente refletindo-se na qualidade das amostras produzidas. Do ponto de vista da concentração de portadores, varia muito de acordo com a qualidade dos filmes, mas usualmente é aproximadamente 1016 cm"3. O maior valor já publicado para o ZnO dopado do tipo-n é = 1020 cm"3 e quando os seus portadores majoritários são buracos, ou seja, dopado do tipo-p pode chegar a ~ 1019 cm"3. Because it is a wide gap semiconductor and has high exciton bonding energy, ZnO draws a lot of attention in applications such as devices. For example, a device made of wide gap material may exhibit high breaking voltage, low noise generation and may operate at high temperatures and high power. Thus the performance of electronic devices produced with this material is different in low and high electric fields. On the other hand, the electrical properties of ZnO films are often difficult to quantify because they strongly depend on the synthesis and / or deposition and / or growth methodology, consequently reflecting on the quality of the samples produced. From the standpoint of carrier concentration, it varies widely according to the quality of the films, but is usually approximately 10 16 cm "3. The highest value ever published for n-type doped ZnO is = 10 20 cm " 3 and when its majority carriers are holes, ie p-doped, it can reach ~ 10 19 cm "3 .
Os polímeros orgânicos condutores por outro lado são caracterizados pela presença de uma conjugação π estendida, na sua cadeia principal e por propriedades especificas, tais como: baixas energias de transições óticas, baixos potenciais de ionização, altas afinidades eletrônicas. Portanto, eles são mais facilmente oxidados e reduzidos do que os polímeros convencionais. Estes materiais são sintetizados pela polimerização, via acoplamento oxidativo, de um monômero em solução, contendo, geralmente, anéis aromáticos ou ligações múltiplas carbono-carbono. O processo de polimerização pode ser químico ou eletroquímico, e o nível de condutividade destes materiais, situa-se na faixa de 10+2 a 10"11 S.cm"1, alem disso estes materiais combinam as características dos plásticos com as propriedades elétricas, ópticas e magnéticas dos metais ou semicondutores e se apresentam como um material alternativo para substituir os semicondutores inorgânicos na eletrônica devido a sua diversidade e facilidade de síntese, preparação de filmes finos a partir de uma solução do polímero por "spin coating" ou "dip coating", e principalmente devido ao seu baixo custo. As propriedades mecânicas (flexibilidade, resistência e elasticidade) destes materiais permitem a sua utilização na fabricação de novos dispositivos eletrônicos formados completamente de material plástico. Alem disto apresentam propriedades eletrocrômicas e suas propriedades luminescentes são comparáveis ou superiores às dos semicondutores inorgânicos, possibilitando assim a sua utilização na fabricação LEDs, na fabricação de dispositivos de junção, díodos Schottky e FETs. Entre os polímeros condutores a polianilina tem se destacado em parte devido as suas propriedades elétricas poderem ser reversivelmente controladas pela mudança do estado de oxidação da cadeia principal ou pela protonação dos átomos de nitrogénio imina da cadeia polimérica. Além disso, a forma condutora da polianilina apresenta uma excelente estabilidade térmica e ambiental. Conductive organic polymers, on the other hand, are characterized by the presence of an extended π conjugation in their main chain and specific properties such as low energies of optical transitions, low ionization potentials, high electronic affinities. Therefore, they are more easily oxidized and reduced than conventional polymers. These materials are synthesized by the oxidative coupling polymerization of a monomer in solution, generally containing aromatic rings or carbon-carbon multiple bonds. The polymerization process can be chemical or electrochemical, and the conductivity level of these materials is in the range of 10 + 2 to 10 "11 S.cm " 1 , in addition these materials combine the characteristics of plastics with the electrical properties. and optical properties of metals or semiconductors and are presented as an alternative material to replace inorganic semiconductors in electronics due to their diversity and ease of synthesis, preparation of thin films from a polymer solution by spin coating or dip coating ", and mainly due to its low cost. The mechanical properties (flexibility, strength and elasticity) of these materials allow their use in the manufacture of new electronic devices formed entirely of plastic material. In addition they have electrochromic properties and their luminescent properties are comparable or superior to those of inorganic semiconductors, thus enabling their use in the manufacture of LEDs, in the manufacture of junction devices, Schottky diodes and FETs. Among the conducting polymers polyaniline has stood out in part because its electrical properties can be reversibly controlled by changing the oxidation state of the main chain or by protonating the nitrogen imine atoms of the polymer chain. In addition, the conductive form of polyaniline exhibits excellent thermal and environmental stability.
FUNDAMENTOS DA INVENÇÃO: BACKGROUND OF THE INVENTION:
A presente invenção refere-se a um processo original de fabricação de filmes finos nanoestruturados de oxido de zinco, polímeros condutores e filmes metálicos, para o desenvolvimento de heterojunções com propriedades elétricas distintas, ou seja, diodos retificadores caracterizados por conduzir eletricidade somente em uma das polarizações como também heterojunções com propriedades de um Varistor, dispositivo caracterizado por conduzir eletricidade tanto na polarização direta quanto na reversa. Isto é, possuem propriedades de resistores variáveis, de forma que à medida que aumenta-se a diferença de potencial aplicada ao varistor, sua resistência elétrica diminui.  The present invention relates to an original process of manufacturing nanostructured zinc oxide thin films, conductive polymers and metallic films for the development of heterojunctions with distinct electrical properties, ie rectifying diodes characterized by conducting electricity in only one of the polarizations as well as heterojunctions with properties of a Varistor, a device characterized by conducting electricity in both forward and reverse polarization. That is, they have variable resistor properties, so that as the potential difference applied to the varistor increases, its electrical resistance decreases.
O dispositivo é constituído de uma estrutura em forma de um sanduíche como mostra as figuras 1 e 2, composto de um suporte que pode ser plástico, vidro ou qualquer outro substrato que serve de suporte mecânico para a confecção do dispositivo (1), sobre este suporte é depositada através de evaporação térmica um filme metálico que pode ser ouro o qual serve de contato elétrico (5), sobre esta superfície é depositada um filme nanométrico de polianilina através da técnica spin- coating (4), ou outra técnica de produção de nanofilmes, em seguida um contato nanométrico de oxido de zinco através da técnica evaporação térmica é depositado sobre esta superfície (3) e finalmente um nanofilme de alumínio ou ouro (2) é depositado para fazer o segundo contato elétrico da heterojunção como mostra a figura 2, esta configuração possibilita a caracterização elétrica dos dispositivos, como mostram os resultados das figuras 3-5. Figura 3 mostra as Curvas características I x V da heterojunção AI/ZnO/PANI/Au. para dispositivos processados com ZnO em forma de contato com espessura típica de 100 nm e a PANI no estado dopado, observa-se que esta resposta elétrica é característica de um dispositivo do tipo p-n. com características retificadoras. The device consists of a sandwich-shaped structure as shown in figures 1 and 2, consisting of a support which may be plastic, glass or any other substrate that serves as a mechanical support for making the device (1) thereon. A gold-plated metallic film which serves as an electrical contact (5) is deposited by thermal evaporation. A nanometer polyaniline film is deposited on the surface by spin-coating technique (4), or another technique for producing nanofilms, then a zinc oxide nanometric contact through the thermal evaporation technique is deposited on this surface (3) and finally an aluminum or gold nanofilm (2) is deposited to make the second electric contact of the heterojunction as shown in figure 2 , this configuration allows the electrical characterization of devices, as shown in the results of figures 3-5. Figure 3 shows the characteristic I x V curves of the AI / ZnO / PANI / Au heterojunction. For devices processed with typical 100 nm contact-shaped ZnO and doped NIBP, This electrical response is characteristic of a pn type device. with rectifying characteristics.
Figura 4 mostra um segundo tipo de curvas características I x V obtidas com os dispositivos processados com o ZnO em forma de contato com espessuras de 100 nm, 200 nm e 350 nm, respectivamente, onde em (d) é mostrado a comparação das curvas Figure 4 shows a second type of I x V characteristic curves obtained with devices processed with contact-shaped ZnO with thicknesses of 100 nm, 200 nm and 350 nm, respectively, where in (d) is shown the comparison of the curves.
I x V características destes três dispositivos, me todos os casos a PANI encontra-se no estado desdopado. Observa-se que neste caso o dispositivo apresenta uma resposta elétrica característica de um dispositivo do tipo Varistor, ou seja, o dispositivo conduz nas duas polarizações (direta e reversa) com uma tensão de ruptura que varia entre ± 40 volts dependendo das condições de fabricação do dispositivo apresentando coeficiente de não linearidade (a) em torno de 15. Observa-se que as curvas I x V tem características não lineares e apresentam um alto grau de simetria independente da espessura do contato de ZnO utilizado. Visto que uma das propriedades mais importantes de um varistor é sua característica I x V não linear, percebe-se o potencial para aplicação dessas heterojunções com varistores. Em um dispositivo tipo varistor o ideal é que o mesmo apresente alto valor de coeficiente de não linearidade α (coeficiente que define a não linearidade de um varistor). I x V characteristics of these three devices, but in all cases the NIBP is in the unpopulated state. It is observed that in this case the device presents a characteristic electric response of a Varistor type device, that is, the device conducts in both polarizations (direct and reverse) with a rupture voltage that varies between ± 40 volts depending on the manufacturing conditions. Nonlinearity coefficient (a) around 15. It is observed that the curves I x V have nonlinear characteristics and present a high degree of symmetry independent of the thickness of ZnO contact used. Since one of the most important properties of a varistor is its nonlinear I x V characteristic, one realizes the potential for application of these heterojunctions with varistors. In a varistor-type device it is ideal to have a high value of nonlinearity coefficient α (coefficient that defines the nonlinearity of a varistor).
Figura 5. mostra a comparação das curvas I x V entre um varistor comercial de I V e dois dispositivos processados a base de ZnO e PANI. (a) Heterojunção com o ZnO com espessura típica de 100nm e a PANI no estado desdopado, (b) Varistor comercial e (c) Heterojunção com o ZnO com espessura típica de 200nm e a PANI no estado desdopado. Podemos concluir que o nosso dispositivo tem características semelhantes ao comercial com um adicional de que é possível modificar a tensão de ruptura do dispositivo de acordo com os parâmetros de fabricação. O fundamento desta invenção tem como base o fato do polímero condutor polianilina pode ser preparada em diversos estados de dopagem e grau de oxidação. Quando o polímero encontra-se no estado dopado o dispositivo tem características de uma junção p-n, por outro lado quando o polímero encontra- se no dispositivo no estado semi dopado ou desdopado a heterojunção apresenta característica de um dispositivo Varistor. As propriedades elétricas dos varistores convencionais não só dependem de fatores como estequiometria da superfície do óxido, metodologia de preparação do pó, temperatura e atmosfera de calcinação, mas principalmente da grande área especifica devido à baixa densificação do óxido. Além disso, o processo de fabricação dos varistores convencionais envolve altas temperaturas de processamento (em torno de 1200 °C), consequentemente, o controle preciso de altas temperaturas é difícil, e envolve também maior gasto de energia. A voltagem de varistores convencionais é determinada através da espessura do material (geralmente é processado em formato cilíndrico) e do tamanho de grão do material (por exemplo, ZnO), onde cada contorno de grão comporta-se como um microvaristor de 2 a 3V. Dessa forma, a relação que determina a voltagem de um varistor comercial é dada pela equação Vn = (3V)n, onde n é o número médio de contorno de grão entre os eletrodos, por outo lado a espessura do Varistor D é dado por D = (n + 1)d onde é o tamanho médio dos grãos. Figure 5 shows the comparison of I x V curves between a commercial IR varistor and two ZnO and NIBP based devices. (a) Heterojunction with the typical 100nm thick ZnO and the NIPP in the unpopulated state, (b) Commercial varistor and (c) Heterojunction with the typical 200nm thick ZnO and the NIPP in the unpopulated state. We can conclude that our device has commercial-like characteristics with an additional that it is possible to modify the breaking voltage of the device according to manufacturing parameters. The basis of this invention is based on the fact that the polyaniline conductive polymer can be prepared in various doping states and oxidation degree. When the polymer is in the doped state the device has characteristics of a pn junction, on the other hand when the polymer is in the semi-doped or undoped state device the heterojunction is characteristic of a Varistor device. The electrical properties of conventional varistors depend not only on factors such as oxide surface stoichiometry, powder preparation methodology, temperature and calcination atmosphere, but mainly on the large specific area due to the low oxide densification. In addition, the manufacturing process of conventional varistors involves high processing temperatures (around 1200 ° C), therefore precise control of high temperatures is difficult and involves also higher energy expenditure. The voltage of conventional varistors is determined by the thickness of the material (usually processed in cylindrical shape) and the grain size of the material (eg ZnO), where each grain boundary behaves as a 2 to 3V microvistor. Thus, the ratio that determines the voltage of a commercial varistor is given by the equation V n = (3V) n, where n is the average number of grain boundaries between the electrodes, on the other hand the thickness of Varistor D is given by D = (n + 1) d where is the average grain size.
Com relação a heterojunção ZnO/PANI apresentada nesta patente o controle da voltagem do varistor (tensão de ruptura) é feita através do controle da espessura do ZnO, ou seja, aumentando a espessura do ZnO aumenta-se a tensão de ruptura, idêntico ao varistor convencional, entretanto a nossa metodologia permite um controle extra da tensão de ruptura, alem de controlarmos a voltagem do varistor através da espessura do ZnO é possível também controlá-la através da dopagem do polímero. Com a PANI no seu estado desdopado (completamente isolante) é possível obter varistores com tensão ruptura de até 40 V. Por outro lado, quando a PANI está no estado natural (estado que apresenta condutividade baixa) é possível obter varistores com voltagem de 5 V.  Regarding the ZnO / NIBP heterojunction presented in this patent the control of the varistor voltage (rupture voltage) is made by controlling the thickness of ZnO, that is, increasing the thickness of ZnO increases the rupture voltage, identical to the varistor Conventional, however our methodology allows an extra control of the rupture voltage, besides controlling the voltage of the varistor through the thickness of ZnO it is also possible to control it by doping the polymer. With NIBP in its unpopulated (fully insulating) state it is possible to obtain varistors with rupture voltage up to 40 V. On the other hand, when NIBP is in the natural state (state with low conductivity) it is possible to obtain varistors with voltage of 5 V. .

Claims

REIVINDICAÇÕES
1) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR caracterizado por ser constituído de polímero condutor, oxido de zinco e metais. 1) Nano-structured VARISTOR TYPE SEMICONDUCTOR DEVICE characterized by conductive polymer, zinc oxide and metals.
2) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR de acordo com a reivindicação 1 caracterizado pelo polímero condutor ser maciço ou constituído de filmes desses compostos.  Nanostructured variant type semiconductor device according to Claim 1, characterized in that the conductive polymer is solid or composed of films of these compounds.
3) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR de acordo com a reivindicação 2 caracterizado pelo polímero condutor apresentar diversos estados de dopagem e espessura.  Nanostructured VARISTOR TYPE SEMICONDUCTOR DEVICE according to claim 2, characterized in that the conductive polymer has various doping states and thickness.
4) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR de acordo com a reivindicação 1 caracterizado pelo óxido de zinco ser produzido na forma de filmes finos ou material maciço  Nano-structured variant type semiconductor device according to Claim 1, characterized in that the zinc oxide is produced in the form of thin films or solid material.
5) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR de acordo com a reivindicação 4 caracterizado pela estrutura do dispositivo conter óxido de zinco em diversas espessuras.  Nanostructured VARISTOR TYPE SEMICONDUCTOR DEVICE according to claim 4, characterized in that the device structure contains zinc oxide in various thicknesses.
6) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR de acordo com a reivindicação 5 caracterizado pela espessura dos filmes de óxido de zinco está contido no intervalo de medida de 90 a 300 nanometros incluindo seus limites.  The nanostructured variant type semiconductor device according to claim 5 characterized in that the thickness of the zinc oxide films is contained within the range of 90 to 300 nanometers including their limits.
7) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR segundo reivindicação 3, caracterizado pelo polímero condutor encontrar-se no estado desdopado.  Nano-structured VARISTOR TYPE SEMICONDUCTOR DEVICE according to claim 3, characterized in that the conductive polymer is in the disassembled state.
8) DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR segundo reivindicação 3, caracterizado pelo polímero condutor ser a polianilina.  Nano-structured VARISTOR TYPE SEMICONDUCTOR DEVICE according to claim 3, characterized in that the conductive polymer is polyaniline.
9) PROCESSO DE FABRICAÇÃO DE DISPOSITIVO SEMICONDUTOR DO TIPO VARISTOR DE TENSÃO VARIÁVEL caracterizado pelo controle da dopagem do polímero condutor ser o que determina as características elétricas do dispositivo.  9) VARIABLE VOLTAGE TYPE SEMICONDUCTOR DEVICE MANUFACTURING PROCESS characterized by the conductive polymer doping control being what determines the electrical characteristics of the device.
10) PROCESSO DE FABRICAÇÃO DE DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR composto por um suporte de material plástico ou vítreo que serve de suporte mecânico para a confecção do dispositivo, sobre este suporte é depositada através de evaporação térmica um filme metálico o qual serve de contato elétrico, sobre esta superfície é depositada um filme nanométrico de polianilina através da técnica spin-coating, ou outra técnica de produção de nanofilmes, em seguida um contato nanométrico de oxido de zinco através da técnica evaporação térmica é depositado sobre esta superfície e finalmente outro nanofilme metálico é depositado para fazer o segundo contato elétrico da heterojunção 10) MANUFACTURING PROCESS OF MANUFACTURING Nano-STRUCTURED VARISTOR SEMICONDUCTOR DEVICE composed of a support made of plastic or glass which serves as a mechanical support for the preparation From the device, a metallic film which serves as electrical contact is deposited on the substrate by thermal evaporation. On this surface, a nanometric polyaniline film is deposited by spin-coating or other nanofilm production technique, followed by a zinc oxide nanometric contact through the thermal evaporation technique is deposited on this surface and finally another metallic nanofilm is deposited to make the second electrical contact of the heterojunction
11) PROCESSO DE FABRICAÇÃO DE DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR de acordo com a reivindicação 11 caracterizado pelo filme metálico ser de ouro.  A method of manufacturing the nanostructured variant type semiconductor device according to claim 11 wherein the metal film is of gold.
12) PROCESSO DE FABRICAÇÃO DE DISPOSITIVO SEMICONDUTOR NANOESTRUTURADO DO TIPO VARISTOR CONSTITUÍDO DE POLÍMERO CONDUTOR E OXIDO DE ZINCO E METAIS acordo com a reivindicação 11 caracterizado pelo filme metálico ser de alumínio.  12. The manufacturing process of a nanostructured semiconductor device of the Zinc and Oxide Conducting Polymer and Metals according to claim 11, characterized in that the metal film is aluminum.
PCT/BR2010/000141 2009-04-01 2010-04-05 Varistor-type, nanostructured semiconductor device made of conducting polymer, zinc oxide and metals WO2010111764A2 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5464990A (en) * 1992-09-25 1995-11-07 Fuji Xerox Co., Ltd. Voltage non-linear device and liquid crystal display device incorporating same
US6023073A (en) * 1995-11-28 2000-02-08 International Business Machines Corp. Organic/inorganic alloys used to improve organic electroluminescent devices
US6344662B1 (en) * 1997-03-25 2002-02-05 International Business Machines Corporation Thin-film field-effect transistor with organic-inorganic hybrid semiconductor requiring low operating voltages
WO2004029176A1 (en) * 2002-09-24 2004-04-08 E.I. Du Pont De Nemours And Company Electrically conducting organic polymer/nanoparticle composites and methods for use thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5464990A (en) * 1992-09-25 1995-11-07 Fuji Xerox Co., Ltd. Voltage non-linear device and liquid crystal display device incorporating same
US6023073A (en) * 1995-11-28 2000-02-08 International Business Machines Corp. Organic/inorganic alloys used to improve organic electroluminescent devices
US6344662B1 (en) * 1997-03-25 2002-02-05 International Business Machines Corporation Thin-film field-effect transistor with organic-inorganic hybrid semiconductor requiring low operating voltages
WO2004029176A1 (en) * 2002-09-24 2004-04-08 E.I. Du Pont De Nemours And Company Electrically conducting organic polymer/nanoparticle composites and methods for use thereof

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