Abstract: Provided is a method for controlling electrical properties and morphology of a p-type material of a photovoltaic device. The p-type material, such as p-type cadmium telluride, is first subjected to heat treatment in an oxidizing environment, followed by recrystallization in an environment substantially free of oxidants. In one embodiment, the heat treatment step comprises first subjecting the p-type material to an oxidizing atmosphere at a first temperature to getter impurities, followed by second subjecting the p-type material to an oxidizing atmosphere at a second temperature, higher than the first temperature, to develop a desired oxidation gradient through the p-type material.

Abstract: A photovoltaic cell has an n-type polycrystalline layer and a p-type polycrystalline layer adjoining the n-type polycrystalline layer to form a photovoltaic junction. The p-type polycrystalline layer comprises a substantially planar layer portion having relatively large crystals adjoining the n-type polycrystalline layer. The planar layer portion includes oxidized impurities which contribute to obtainment of p-type electrical properties in the planar layer portion.

Abstract: A novel photovoltaic module (10) and method for constructing the same are disclosed. The module (10) includes a plurality of photovoltaic cells (12) formed on a substrate (14) and laterally separated by interconnection regions (15). Each cell (12) includes a bottom electrode (16), a photoactive layer (18) and a top electrode layer (20). Adjacent cells (12) are connected in electrical series by way of a conductive-buffer line (22). The buffer line (22) is also useful in protecting the bottom electrode (16) against severing during downstream layer cutting processes.

Abstract: A pattern of transparent conductive material, such as tin oxide, is formed on a transparent vitreous substrate using a polycrystalline material, such as cadmium or zinc sulfide, to mask the substrate surface while depositing material forming the transparent conductive layer. The polycrystalline material and any overlying transparent conductive material are easily removed by a chemical etch, leaving the desired pattern of transparent conductive material adhering to the substrate. Two electrically conductive patterns may be formed in intersecting relationship and isolated, one from the other. The degree of electrical connection between the two patterns will be a function of the resistance of the polycrystalline material therebetween at points of crossing. In some instances, electroluminescence may be obtained by selecting the proper crystalline material wherein an electrical display may be created by selectively energizing crossing electrical conductors.

Abstract: A pattern of transparent conductive material, such as tin oxide, is formed on a transparent vitreous substrate using a polycrystalline material, such as cadmium or zinc sulfide, to mask the substrate surface while depositing material forming the transparent conductive layer. The polycrystalline material and any overlying transparent conductive material are easily removed by a chemical etch, leaving the desired pattern of transparent conductive material adhering to the substrate. Two electrically conductive patterns may be formed in intersecting relationship and isolated, one from the other. The degree of electrical connection between the two patterns will be a function of the resistance of the polycrystalline material therebetween at points of crossing. In some instances, electroluminescence may be obtained by selecting the proper crystalline material wherein an electrical display may be created by selectively energizing crossing electrical conductors.

Abstract: An apparatus is provided for forming a large area photovoltaic cell into a plurality of photovoltaic cells on a common substrate and preparing the individual cells for an overlying layer of conductive material. A tool bit is urged against the polycrystalline materials forming the heterojunction to remove a preselected pattern and expose a layer of conductive material, tin oxide, on a supporting glass substrate. Tool bit pressure causes fracturing of the crystals to produce defined edges along the tool bit furrow. An electrical arc is produced to vaporize a portion of the exposed tin oxide to electrically isolate the individual photovoltaic cells. Applicator pens coat the edges of the polycrystalline material with preselected insulating films. Finally, a buffer wheel abrades a preselected metal onto the remaining exposed surface of the tin oxide to obtain an improved metallurgical and/or electrical contact between the tin oxide and the subsequent conductor layer.