Showing papers on "Indium tin oxide published in 1986"

Effect of hydrogen plasma treatment on transparent conducting oxides

Abstract: The effect of hydrogen plasma treatment on indium tin oxide (ITO), fluorine‐doped tin oxide (FTO), and indium‐doped zinc oxide (IZO) films has been studied. X‐ray photoelectron spectroscopy analysis shows that ITO and FTO surfaces get reduced to yield elemental indium and tin, respectively. Annealing of the plasma treated films in air leads to re‐oxidation of the reduced surface and the electro‐optical properties are recovered. In contrast, IZO films are not reduced by plasma treatment and show no changes in the electrical and optical properties. The surface of plasma treated IZO films shows a higher binding energy O(1s) peak probably due to OH or OH...O species which appear to form a protective layer against plasma degradation.

Optical properties of transparent and heat‐reflecting indium tin oxide films: Refinements of a model for ionized impurity scattering

Abstract: We compute the dynamic resistivity ρ≡ρ1+iρ2 for a model of heavily n‐doped semiconductors with special regard to transparent and heat‐reflecting In2O3:Sn films. The Sn impurities are ionized and the ensuing electrons occupy part of the In2O3 conduction band as a free‐electron gas (with plasma energy ℏωp). We use pseudopotential arguments to show that the Sn ions act as Coulomb scatterers up to the largest electron densities of practical interest. By representing screening in the electron gas with different models, it was found that exchange and correlation could decrease ρ1 by ≲20% below ℏωp and alter the exponent s in the relation ρ1∝ωs, applying at ℏω>ℏωp, from −3/2 to ∼ −2.

Indium tin oxide/GaAs photodiodes for millimetric-wave applications

Abstract: In the letter we describe improved ITO/GaAs photodiodes for very high-speed applications. For the first time a GaAs device is reported which combines a millimetric wavelength response with a - 3dB bandwidth of ≥ 50 GHz (10 ps FWHM), with a high quantum efficiency in excess of 30% at 820 nm.

Fourier Transform Infrared Reflection Spectroscopy Studies of Organic Films Formed on Inorganic Substrates

Abstract: Reflection absorption spectroscopy on metal surfaces has been applied to reflection spectroscopy on nonmetallic inorganic materials with Fourier transform infrared spectroscopy. The optimal measurement conditions—polarization of incident light and angle of incidence—are discussed on the basis of a calculation using a model of a three-phase system consisting of air, an organic film, and an inorganic substrate. Reflection spectra of stearic acid films on glass substrates were obtained for both perpendicular and parallel polarized incident lights. The optimal measurement condition was for perpendicular polarization, at angle of incidence of 70°, although the signal-to-noise ratio (S/N) of reflection spectra under this condition was ten times less than the S/N of reflection absorption spectra. Reflection spectra on indium tin oxide substrates were obtained for only parallel polarized incident light, and the optimal angle of incidence was 73°. These results were in good agreement with the calculation results.

Thin-film resistor

Abstract: A thin-film resistor comprising a thin film of a nitride of at least one element belonging to groups III-VI of the periodic table. The thin-film resistor has a metal oxide layer comprising at least one metal oxide selected from the group consisting of manganese oxide, iron oxide, cobalt oxide, nickel oxide, zinc oxide, indium oxide, tin oxide and indium tin oxide interposed between the nitride thin film and an electrode for external connection.

Ion‐beam sputtered indium tin oxide for InP solar cells

Abstract: The efficiency of indium tin oxide/indium phosphide (ITO/InP) solar cells depends on the rate of deposition of the ITO and the substrate temperature. In the case of rf sputter deposition, both of these parameters should be maintained as low as possible. However, it is still necessary to produce ITO window layers with as low a sheet resistance and high a transmittance as possible. This paper is concerned with the properties of such films fabricated by ion‐beam sputtering under the above restrictive conditions. In particular, we have investigated the effects of varying the background partial pressure of oxygen, the film thickness, and the rate of deposition on the electro‐optical properties of the films. (i) For very slow deposition rates (∼0.3 A s−1) and low substrate temperatures (<40 °C), resistivities of <7×10−4 Ω cm have been obtained for films of thickness 250–1200 A. This was for a partial pressure of oxygen, <10−6 Torr; for a partial pressure of 4×10−5 Torr, the resistivity of the films increased to...

Process and structure for thin film transistor matrix addressed liquid crystal displays

Abstract: A thin film FET switching element, particularly useful in liquid crystal displays, employs a set of special materials to ensure compatibility with the indium tin oxide of a pixel electrode layer used as transparent conductive material in liquid crystal display devices. These materials include the use of titanium as a gate electrode material and the use of aluminum as a material to enhance electrical contact between source and drain pads and an underlying layer of amorphous silicon. The apparatus and process of the present invention provide enhanced fabrication yield and device reliability.

Plasma‐assisted metalorganic chemical vapor deposition of ZnSe films

Abstract: ZnSe thin films were grown by plasma‐assisted metalorganic chemical vapor deposition (MOCVD). Plasma‐assisted MOCVD is a technique combining rf glow discharge decomposition (at 13.56 MHz) with conventional metalorganic chemical vapor deposition. This process may offer several advantages such as low‐temperature growth, high chemical reactivity, cleaning effect of substrate surface, and good surface morphology. The metalorganic sources used were diethylzinc and diethylselenide. The epitaxial films were obtained at the low substrate temperature of 250 °C by plasma‐assisted MOCVD. The grown films showed excellent surface morphology and uniformity over a large area. These films were applied to Al/ZnSe:Mn/ITO (indium tin oxide) dc‐operated electroluminescent cells. As a manganese source, di‐π‐cyclopentadienyl manganese [(C5H5)2Mn] was successfully used.

Method of producing transparent, haze-free tin oxide coatings.

Abstract: A method of producing transparent, haze-free tin oxide coatings on glass by chemical vapor deposition from vaporized liquid monophenyltin trichloride. The produced glass is used to prepare double glassed window structures.

Method of producing thin film electroluminescent structures

Abstract: Method of producing a thin film electroluminescent device by sputtering a first transparent electrode of indium tin oxide or tin oxide onto a glass substrate, sputtering a layer of insulating material, for example barium tantalate, over the transparent electrode, and then forming a phosphor layer of zinc sulfide with manganese as an activator on the layer of insulating material. To form the phosphor layer electrical energy is applied to a target containing elemental zinc in an atmosphere containing hydrogen sulfide and argon to cause sputtering therefrom. Elemental zinc reacts with the hydrogen sulfide to deposit a layer of zinc sulfide over the layer of insulating material. The manganese is cosputtered either from a separate target or from a single target incorporating both zinc and manganese.

Thin film el device

Abstract: PURPOSE: To facilitate the patterning of a light emitting layer and obtain a multicolor EL device by patterning a light emitting layer directly by using photosensitive compound for the light emitting layer and directly patterning the light emitting layer by photo processing. CONSTITUTION: As an anode 2, ITO(indium tin oxide) film is formed on a glass substrate 1, and then a phthalocyanine layer as a positive hole injection layer 3 is formed and a photosensitive light emitting layer is formed on the layer by spin coating using an aqueous solution which is crosslinked by ultraviolet ray radiation. When ultraviolet rays are applied to the layer through a mask, the exposed parts are crosslinked and hardened and non-exposed parts are removed by washing with water and in this way patterning is completed. Finally, indium layer as a cathode is formed. By applying direct current between the anode 2 and the cathode 5, orange-color light owing to rhodamine B is emitted. Like this, the light emitting layer 4 is patterned and organic thin film EL device which can emit multicolor light is obtained. COPYRIGHT: (C)1991,JPO&Japio

Device for detecting radioactive rays

Abstract: In an X-ray detecting device for an X-ray computed tomography scanner, an indium tin oxide layer is deposited on a surface of a rectangular scintillator element which opposes X-ray incident surface thereof. The other surfaces of the element are coated with a light reflecting layer. An amorphous silicon film is formed on the indium tim oxide layer to form surface barrier type photo-diode and an electrode is further deposited on the amorphous silicon film. Incident X-rays are converted into light rays in the scintillator element, and light rays are reflected from the reflecting layer to the surface barrier type photo-diode and converted into an electric signal, which is picked up by the electrode.

Zinc oxide multilayers for solar collector coatings.

Abstract: A solar selective coating has been fabricated by capping black zinc oxide with a transparent zinc oxide heat mirror film. Deposition onto glass substrates was accomplished by reactive bias sputtering. The zinc oxide multilayer structure had a solar absorptance of 0.90 and an IR emittance of 0.26. Suggestions are made for significant improvement of solar selective performance.

Tin oxide coated article

Abstract: A tin oxide coated article characterized by including a transparent, haze-free tin oxide coating on a substrate, such as glass. The tin oxide coating is formed by deposition from a liquid coating composition including an organotin compound, such as an alkyltin trichloride, and a haze-reducing additive, such as a fluorocarboxylic acid or acid anhydride.

Laser‐induced damage to spray pyrolysis deposited transparent conducting films

Abstract: Laser‐induced damage study of transparent conducting coatings of tin oxide prepared by spray pyrolysis has been made using a dye Q‐switched Nd:glass laser emitting 25‐ns (FWHM) pulses at 1062 nm. For comparison tin oxide films prepared by chemical vapor deposition (CVD) method and indium tin oxide (ITO) prepared by the reactive rf sputtering method have also been damage tested. The study reveals that the spray pyrolysis method yields good electrical and optical quality films with a damage threshold value of 5.2±0.3 J/cm2. Though CVD technique provides the highest damage threshold coatings (14.2±0.6 J/cm2), their electrical characteristics and uniformity are inferior to rf‐sputtered ITO films which have the best electrical properties and the lowest damage threshold values (1.3±0.1 J/cm2).

Properties of Indium Tin Oxide Films Prepared Using Reactive RF Magnetron Sputtering

Abstract: The results obtained upon reactively RF sputtering indium - tin oxide (ITO) films are presented. It is found that while the amount of oxygen in the chamber is very critical in determining the properties of the films, it is easy to deposit reproducible films even at low oxygen concentrations when using an oxide target. At concentrations of oxygen below 2 vol% the films deposited exhibit almost metallic conductivities, while retaining an average transparency in the visible range of over 85%. The resistivity of these films increases with the oxygen concentration in the chamber, but the transition is not as sharp as that observed upon sputtering a metal target. These films are found to have very good “figures of merit” and are promising in their use as transparent conductors.

SOI TFT's with directly contacted ITO

Abstract: N-channel Al-gate thin-film transistors (TFT's) were fabricated on a silicon on insulator (SOI). Indium tin oxide (ITO) was deposited directly on the n+ silicon layer of the TFT. The contact resistance between the ITO and the n+ silicon layer increases with thermal annealing. The low temperature (200°C) lift-off method of ITO is applied to achieve high-quality TFT's for active matrices in liquid crystal displays (LCD's).

Effect of plasma exposure on the performance of indium tin oxide/InP solar cells prepared by radio‐frequency and ion‐beam sputtering

Abstract: Previous work has shown that the performance of p‐type single crystal/n‐type thin film indium tin oxide (ITO) solar cells, can be enhanced by exposing the substrates (InP) to a very low power rf plasma prior to deposition of the ITO and by depositing the ITO very slowly. The mechanism underlying this enhancement is the subject of this experimental investigation. The principal variables studied were the duration of the low power plasma exposure (LPPE), the doping density of the substrate, and the methods of depositing the ITO. Comparison of the cells has been made on the basis of their current/voltage characteristics and their quantum efficiency. The analysis is consistent with there being a thin n‐type layer at the interface between the InP and the ITO. For the ion‐beam deposited ITO, the n‐type layer is vanishingly small but for the rf deposited cells it is 70–100 A thick; the thickness reducing with longer LPPE. The thickness of this layer appears to control the device performance; the cells with thicker layers have much larger open‐circuit voltage and somewhat lower currents, whereas the reverse is true for thinner layers.Previous work has shown that the performance of p‐type single crystal/n‐type thin film indium tin oxide (ITO) solar cells, can be enhanced by exposing the substrates (InP) to a very low power rf plasma prior to deposition of the ITO and by depositing the ITO very slowly. The mechanism underlying this enhancement is the subject of this experimental investigation. The principal variables studied were the duration of the low power plasma exposure (LPPE), the doping density of the substrate, and the methods of depositing the ITO. Comparison of the cells has been made on the basis of their current/voltage characteristics and their quantum efficiency. The analysis is consistent with there being a thin n‐type layer at the interface between the InP and the ITO. For the ion‐beam deposited ITO, the n‐type layer is vanishingly small but for the rf deposited cells it is 70–100 A thick; the thickness reducing with longer LPPE. The thickness of this layer appears to control the device performance; the cells with thicke...

Tandem photovoltaic devices

Abstract: A photovoltaic device (10) includes an optically transparent, electrically conductive layer (22) and a second electrically conductive layer (13) both of which provide contact areas for electrodes. The photovoltaic device (10) consists of a plurality of at least two cells (11/12) in a tandem configuration. A first cell (11) may be made of an amorphous semiconductor and a second cell (12) may be made of two semiconductor layers (15/14) of different compounds having a heterojunction (16) therebetween. The amorphous semiconductor layer (21) of the one cell (11) has a surface which contacts the optically transparent, electrically conductive layer (22). One of the two semiconductor layers (14) of the second cell (12) has a surface which electrically contacts the second conductive layer (13). Means (18) for example a transparent, conductive layer, such as indium tin oxide, or a tunnel diode structure are provided to connect another surface of the first cell (11) and another surface to the second cell (12) so that the cells (11/12) are optically and electrically in series.

Studies on the optical properties and the burstein‐moss shift inindium tin oxide films

Abstract: Optical properties of de sputtered indium tin oxide (ITO) films are studied in the range of photon energies 0.7 to 4.5 eV. The data are analysed in the light of existing theories indicating Burstein- Moss shift. Correlation among carrier concentration, plasma frequency, and optical band gap indicates an effective mass me* = 0.56me, me being the free electron mass. Structural details of ITO films deposited on glass substrates are analysed by X-ray diffraction pattern.

Fluorine-doped tin oxide−selenium heterojunction for photovoltaic conversion

Abstract: Selenium, being a low-cost material and readily available in high purity form, is attracting interest for solar cell applications. It has been calculated theoretically [1] that selenium-based heterojunction solar cells can have an efficiency as high as 20%. Shaw and Ghosh [2] have reported that cells with efficiency better than 10% can be fabricated with selenium in the form of heterojunctions. The results on CdO-CdSe-Se and SnO2-CdSe-Se heterojunctions [2, 3] indicate a conversion efficiency of the order of 3%. Nakada and Kunioka [4] have developed an indium tin oxide (ITO)-selenium heterojunction solar cell having an efficiency of 3.3%. In this letter we report the results of fluorine-doped tin oxide (FTO)-selenium heterojunctions. Transparent FTO films were prepared on chemically and ultrasonically cleaned glass substrates using the spray pyrolysis technique described earlier [5]. The FTO films so obtained show optical transmittance of 84% for a wavelength of 540 nm with a sheet resistance of 10 f~/D at room temperature. No antireflection coating was done prior to deposition of FTO. High-purity selenium (99.999%) obtained from Nuclear Fuel Complex (India) was thermally deposited from a quartz crucible onto the FTO-coated glass slides kept at room temperature. On some of the samples, an ultrathin tellurium layer (1 to 5 nm) was deposited prior to selenium coating. The selenium film was intentionally grown as amorphous to have better control over thickness and surface morphology. A silver overlayer was grown on the selenium to give electrical contact and back-field reflectance. A conducting silver paste was used to take electrical contacts from the silver film. All the vacuum deposition was done in a Hind high-vacuum (India) coating unit 12A4 at a pressure better than 10 -5 torr using a liquid nitrogen trap. The thickness of the film was measured using an FECO interferometer. The selenium sandwich was subjected to thermal shocks at 200 ° C to convert high resistivity amorphous selenium to low resistivity polycrystalline selenium.

A novel TFEL device using a high-dielectric-constant multilayer ceramic substrate

Abstract: A novel composite-structure ac EL device using thin films and a ceramic substrate has been developed. A light-emitting thin film (ZnS:Mn) and ITO electrodes are deposited on a multilayer ceramic substrate consisting of a very high-dielectric ceramic insulating layer (e s ∼ 104), internal printed electrodes, and a ceramic base plate. This device features low operating voltage (40-80 V), breakdown-failure-free operation, and high legibility.