GB393967A - Improvements in and relating to photo-electric cells and methods of producing same - Google Patents

Abstract

393,967. Photo-electric cells. STEVENS, A. H., 5, Quality Court, Chancery Lane, London.-(G-M Laboratories, Inc. ; 1731, Belmont Avenue, Chicago, U.S.A.) Sept. 15, 1931, No. 25877. Drawings to Specification. [Class 39 (i).] A photo-electric cathode is prepared by (a) coating a base, for example of copper, silver, magnesium or gold with a paste or solution containing one or more oxides, oxidizing salts, or oxygen-bearing salts decomposable by heat to form oxides, (b) reducing the oxide and reoxidizing it, and (c) depositing photoelectric material such as alkali or alkalineearth metal on the reoxidized surface. A mixture of an oxide of barium, strontium, silver, gold, or copper, or potassium dichromate, or carbonate of barium or strontium with a solution of nitrocellulose in methvl alcohol and amyl acetate is sprayed on the cathode which is then treated to remove nitrocellulose and reduce carbonate to oxide : or one or more of the oxides of barium, strontium, silver, gold. or copper, or potassium dichromate are mixed with barium nitride and applied to the cathode and heated. Silver oxide is reduced to silver by heating to 300-350‹ C., and reoxidized by heating in oxygen with or without inert gas. Alkali or alkaline-earth metal is deposited by heating a pellet containing, for example, a mixture of a cµsium or potassium salt with calcium. Excess metal is absorbed in a lead glass stem, or removed by heating and evacuating the cell. Concentration of the alkali metal on the surface is increased by passing a glow discharge through inert gas with the cathode positive, or decreased by a similar discharge with the cathode negative.