Showing papers on "Indium tin oxide published in 1981"

Stability of n‐i‐p amorphous silicon solar cells

Abstract: Unencapsulated, amorphous silicon indium tin oxide/n‐i‐p/stainless‐steel solar cells were tested for stability. All cells have excellent shelf life. Changes occur during exposure to light, but can be controlled by the deposition conditions of the amorphous silicon. The changes are due to trapping and recombination of optically generated carriers in the i layer, and are reversibly annealed out above 175 °C. Preliminary life tests on two relatively stable cells showed a small initial drop to 5%, followed by a weak logarithmic decay that predicts only ∼20% further decrease in efficiency after 20 years in sunlight. Work is continuing on improving the efficiency and stability of these cells.

On resolving the anomaly of indium-tin oxide silicon junctions

Abstract: Experimental evidence is presented to resolve the anomalous rectifying behavior of indium-tin oxide (ITO)/silicon junctions. Previous work has demonstrated that the rectifying direction for this heterojunction depends on the method used to deposit the ITO. It is shown here that the cause for this is the existence of damaged surface layers in junctions subject to ion beam processing. Irrespective of the material deposited and irrespective of the doping type, ion-beam sputtering tends to cause the silicon band edges to bend downwards at the surface. It is for this reason that ion-beam deposited ITO gives a rectifying junction on p-Si and an ohmic contact on n-Si.

Indium oxide/n-silicon heterojunction solar cells

Abstract: A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%

Secondary Electron Emission Yields

Abstract: The secondary electron emission (SEE) characteristics for a variety of spacecraft materials were determined under UHV conditions using a commercial double pass CMA which permits sequential Auger electron electron spectroscopic analysis of the surface. The transparent conductive coating indium tin oxide (ITO) was examined on Kapton and borosilicate glass and indium oxide on FED Teflon. The total SEE coefficient ranges from 2.5 to 2.6 on as-received surfaces and from 1.5 to 1.6 on Ar(+) sputtered surfaces with 5 nm removed. A cylindrical sample carousel provides normal incidence of the primary beam as well as a multiple Faraday cup measurement of the approximately nA beam currents. Total and true secondary yields are obtained from target current measurements with biasing of the carousel. A primary beam pulsed mode to reduce electron beam dosage and minimize charging of insulating coatings was applied to Mg/F2 coated solar cell covers. Electron beam effects on ITO were found quite important at the current densities necessary to do Auger studies.

Conductivity modulation in indium oxide films by oxygen pressure variations

Abstract: The electrical conductivity of indium oxide films prepared by reactive evaporation of indium is shown to be modulated by adusting the partial pressure of oxygen over the film after its formation. This effect is attributed to changes in the extent of nonstoichiometry of the oxide, which seems to be caused by the incorporation into or extraction of oxygen from the oxide film. The effect is found to be reversible, temperature‐dependent, and to become smaller as the film thickness increases.

Method of manufacturing a heat-reflecting filter

Abstract: A method of making a heat-reflecting filter consisting of a tin-doped indium oxide layer on a carrier. A tin-doped indium oxide layer is provided on a carrier by spraying a heated carrier with a solution of an indium salt and a tin salt. The layer is then reduced at 350°-400° C. by means of a gas flow of hydrogen, nitrogen together with oxygen or air.

Tandem solar cell

Abstract: A high efficiency tandem solar cell is fabricated by evaporating a layer (2) of optically transparent conducting material, such as indium tin oxide, on a substrate layer (1) of crystalline silicon to form a photo-responsive p/n junction (3). A layer (4) of amorphous silicon is plasma deposited on the layer (2) and is n-doped in the region (5) in contact with the layer (2). A thin film (8) of optically transparent metal is evaporated on the layer (4) to form a photo-responsive Schottky barrier (9). A layer (12) of anti-reflective material, such as Ti02, is applied to the film (8). Light incident on the upper surface (13) has higher energy photons absorbed in the higher bandgap amorphous material layer (4) and lower energy photons pass through the transparent conductor layer (2) to a point of absorption in the lower energy gap crystalline material layer (1).

Liquid crystal display electrode prodn. from indium tin oxide mixt. - by vacuum evapn. of partly reduced oxide, etching and tempering until transparent

Abstract: In th prodn. of a liq. crystal display (LCD) device, a transparent substrate is given a partly transparent coating, esp. under 1000 A thick, of In and Sn oxides by vacuum deposition. For the prodn. of layers resistant to liq. crystals, a mixt. obtd. by treating a mixt. of 75-95 (90) mole % In2O3 and 5-25 (10)% SnO2 with a reducing agent under conditions insufficient for complete redn. is evaporated from a crucible of reducing substance in an O2 atmos. at a pressure of 5 x 10 exp. -r5 to 3 x 10 exp. -3 mmHg. This vapour is deposited on the substrate at a rate of 0.1-1.5 nm/s. After etching the coating to form an electrode, it is tempered in an atmos. contg. 02 to make it completely transparent. The electrical resistance of the oxidn. coating is as low as possible and it is chemically stable.

Analysis of indium-phosphide/indium tin oxide solar cells

Abstract: The mechanisms are investigated that underlie the operation of p-InP/n-ITO solar cells fabricated by depositing thin films of ITO onto InP substrates by both RF sputtering and ion-beam sputtering. The RF sputtered devices behave like SIS or heterojunction cells. The ion-beam sputtered cells behave more like buried homojunction devices. It is shown that the properties of these cells depend not only on the method of fabrication, but also on several other complicating effects which occur before, during and after deposition of the ITO. (LEW)

Efficient Solar Cells on Polycrystalline and Highly Defected Substrates Using Ion Sputtered Indium Tin Oxide

Abstract: Indium tin oxide (ITO)/silicon solar cells of practical size (∿ 4 cm2 ) and efficiency (> 11% total area) have been fabricated using an optimized ion beam milling/sputter deposition and low pressure oxide growth process. Results for a single crystal silicon substrate and four potentially low cost polycrystalline substrates are compared. Photovoltaic performance parameters of cells formed on the best polycrystalline material are essentially identical to those of a representative single crystal device.

Solar Cells Based on Indium Phosphide

Abstract: The objectives of the overall programme of work, part of which is reported here, are to: i) study the fundamental physics of solar cells based on the nearly ideal solar material indium phosphide(InP). ii) to demonstrate the feasibility of sputter deposition of n-type window layers in connection with our programme on all sputtered CdS/Cu2S cells. iii) to develop InP/CdS cells for high concentration applications. This paper is concerned specifically with aspects i) and ii) above.

Transparent, Conductive Layers of Sprayed Indium Tin Oxide in Backwall Cu2S-CdS Cells

Abstract: In this paper, we present the experimental results on the transparency T and the square resistance RO of Indium Tin Oxide layer (ITO).We show the variation of T and RO with the thickness t of ITO layer. Then, we compute the influence of T and RO on the cell efficiency n; we deduce the optimal thickness in order to minimize losses introduced by the ITO layer.