Showing papers on "Indium tin oxide published in 1977"

n‐indium tin oxide/p‐indium phosphide solar cells

Abstract: n‐indium tin oxide/p‐indium phosphide (n‐ITO/p‐InP) solar cells have been prepared by ion‐beam deposition of indium tin oxide on p‐InP single‐crystal substrates. The cells have a solar power conversion efficiency of 14.4% at air mass 2 (AM2) when provided with antireflection coatings.

Magnetron dc reactive sputtering of titanium nitride and indium tin oxide

Abstract: Magnetron dc reactive sputtering of TiN and ITO are sensitive to the design and operating parameters of the magnetron. Plasma confinement, current density, voltage, water cooling of the target, and the ratio of argon to the reactive gas are the important operating parameters. The TiN and ITO film composition was examined by x‐ray diffraction. TiN fractional cross sections were examined by a SEM to determine film microstructure. The TiN films were thick enough to show a transition structure consisting of densely packed fibrous grains. The ITO films were too thin to show any structure.

Electrochemical Patterning of Tin Oxide Films

Abstract: Interest in tin oxide films has grown recently because of their potential application for solar cell structures. The high conductivity of doped tin oxide, coupled with a high transmission coefficient to light from wavelengths in the violet into the infrared, makes it well suited for transparent conductive antireflection coatings and for forming heterojunctions with silicon or gallium arsenide. An additional advantage of tin oxide for such applications is its durability under harsh ambients. For example, tin oxide is not attacked at room temperature by either concentrated acids such as nitric, sulfuric, hydrochloric, and hydrofluoric acids, or by concentrated bases such as ammonium, sodium, and potassium hydroxides. However, this property makes it a difficult material to etch for the purpose of making connection patterns or test cell structures. Sputter etching has been used for patterning tin oxide films, but this technique is slow and requires the dedication of an expensive vacuum system for this purpose. The only alternative technique that has been reported in the literature is the HCl-zinc powder method. However, this technique is difficult to use for large area structures and results in extremely poor edge definition. This note describes an electrochemical technique developed to pattern tin oxide filmsmore » with resolutions limited only by the photolithographic process.« less

Indium—Tin—Oxide—Silicon heterojunction photovoltaic devices

Abstract: We have fabricated heterojunction photovoltaic devices consisting of RF-sputtered, highly transparent, and conductive indium-tin-oxide (IT0) films deposited onto both amorphous or crystalline Si. The ITO-amorphous-Si devices exhibit photovoltaic energy-conversion efficiencies of the order of 0.01 percent for the 100-mW/cm2 white light of a tungsten-halogen lamp. However, the relatively high photoresponse of these devices in the blue-UV spectral region leads to a photovoltaic conversion efficiency of approximately 0.5 percent for monochromatic light of wavelength 400 nm. The ITO-crystalline-Si devices exhibit terrestrial solar-cell efficiencies of the order of 1 percent. The performance of such a cell strongly depends on the insulating interface oxide layer, on the surface-state density, and on the incident-light intensity. A model for the operation of these devices is presented and shown to be in quantitative agreement with the experimental data.

Electrical contact material of silver base alloy

Abstract: An electrical contact material consisting essentially of silver and a small amount of zinc oxide, tellurium oxide, and optionally indium oxide and tin oxide, these oxides being uniformly dispersed in the silver matrix.

Sintered metal oxide semiconductor having electrical conductivity highly sensitive to oxygen partial pressure

Abstract: Tin oxide doped with magnesium oxide or niobium pentoxide and prepared as a sintered material is found to be highly sensitive to oxygen partial pressure both in the presence of free oxygen and in the presence of oxidizable gases, such as carbon monoxide or the lower oxides of nitrogen, and even in the presence of mixtures of both, such as in the exhaust gas of an internal combustion engine. The electrical conductivity varies by substantially more than an order of magnitude in response to a change in the oxygen partial pressure of about one-half an order of magnitude. The doped oxides operate as poor catalysts for the oxidation of oxidizable components of the exhaust gases. Chromium oxide doped with tin oxide shows the effect of an excessively good catalysis from the point of view of range of measurement, but is usable to give a sharp indication of the appearance or disappearance of free oxygen in a gas mixture. Zinc oxide doped with aluminum oxide has a conductivity that is good for measuring the content of free oxygen, but is of questionable value in the presence of a substantial concentration of carbon monoxide.

Metal oxide/indium phosphide devices

Abstract: Devices using a transparent conductive layer of indium oxide or indium tin oxide, and a layer of a direct gap semiconductor material have been found to operate as solar cells and as light emitting devices. Exemplary of such devices is an indium tin oxide/p-InP cell which shows a 12.5% solar power conversion efficiency and also emits a red colored light when biased.

Temperature dependence of the 10.6-microm reflectivity of ITO-coated silicon.

Abstract: R. B. Goldner Tufts University, Electrical Engineering Department, Medford, Massachusetts 02155. Received 20 January 1977. In a previous Letter it was shown that tin-doped indium oxide (ITO)-coated silicon is a useful selective absorber for solar energy conversion applications. Reported in this Letter are the results of measurements that have been made on the temperature dependence of the 10.6-μm wavelength reflec­ tivity of ITO-coated silicon, from room temperature to 475°C. The results indicate that ITO-coated silicon retains its solar selective absorbing properties at least up to 475°C. This is in agreement with data on the temperature independence (from room temperature to about 400° C) of their reflectivity of indium oxide films deposited on quartz substrates, as re­ ported earlier by Kryzhanovskii. Shown in Fig. 1 is a diagram of the configuration used for the measurements. Samples (same as used in the previously reported work) were mounted on a heated stage with an im­ bedded thermocouple and cartridge heaters, all of which were in an evacuated chamber. A mechanical vacuum pump was utilized to evacuate the chamber to pressures ≤IOO μm Hg (0.1 Torr), and a BaF2 window was placed in front of the sample. A CO2 laser, radiating approximately 3-5 W at 10.6 μm, irra­ diated the sample after passing through a ZnSe beam splitter and the BaF2 window. The beam diameter at the sample was less than 2 mm. A shutter was manually translated to block alternately the reflected sample (Rs) and reflected reference

Some properties of indium-tin oxide films

Abstract: Thin films of indium-tin oxide have been deposited by DC diode sputtering from an indium-tin alloy target in an argon, hydrogen and oxygen atmosphere. Films with sheet resistance of 11 ohms/square and 80% light transmission have been obtained. The effect of cathode composition and gas mixture on sheet resistance and optical transmission properties of the films have been studied.

Optical modulation effects in indium oxide films

Abstract: Tin doped indium oxide films produced by chemical vapour deposition and by d.c. sputtering have shown an optical reflectance spectra which can be modulated in the region of the plasma edge in the near infra-red by an electric field applied to the surface through an electrolyte. The effect produced could be quantitatively predicted by a theory developed for surfaces whose optical properties were controlled by their free carrier properties and for the sample being in thin film form.

Low cost, high efficiency solar cells using indium-tin oxide on semiconductor /OSOS/ solar cells

Abstract: ABSTRACT Solar cells consisting of oxide semiconductors deposited on single crystal silicon have been fabricated and have exhibited over 13% conversion efficiency. These cells are best modelled as semiconductor-insulator-semiconductor structure. The oxide semiconductor, Indium Tin Oxide, serves as an anti-reflection coating, a conductive front contact, and one side of the junction. The principal of operation is that the work function difference between the oxide semiconductor and the base semiconductor results in an induced, zero depth p-n junction of the semiconductor. Cells of this type should be less expensive to manufacture than conventional cells using LSSA cost procedures. A detailed investigation of indium sources of supply indicate that indium supply should not limit large scale terrestrial applications.