Improvements in and relating to the manufacture of selenium surfaces

摘要

465,760. Light - - sensitive cells; rectifiers. GENERAL ELECTRIC CO., Ltd., JOHNSON, W. A., and TURNER, H. C. Feb. 27, 1936, No. 5888. [Class 40 (iii)] [Also in. Group XXXVI] A selenium surface for a light-sensitive cell or contact rectifier is manufactured as follows : selenium is melted on to a chemically clean base, such as a nickel-plated iron plate, at a temperature of about 250‹ C. and is also applied by sublimation to a plate of freshly split mica or chemically clean glass. When cool the two selenium surfaces are put together under a pressure of the order of 100 lb./square inch and raised to a temperature of 90 to 140‹ C. for a period of 10 to 40 hours, when the change to the metallic state commences. After slow cooling the pressure is released and the plates separated, the selenium coated metal disc being then subjected to heat treatment at about 170‹ C. to complete the charge of the selenium to the metallic state.