Improvements in or relating to the manufacture of selenium elements such as rectifiers

摘要

5 9 7 , 8 9 9 . Light - sensitive cells. STANDARD TELEPHONES & CABLES, Ltd., and DRIVER, D. L. A. April 27, 1945, No. 10700. [Class 40 (iii)] [Also in Group XXXVI] A selenium element for a photo-electric cell is produced by coating a base-plate with selenium melted thereon and subsequently subjecting the coated base-plate to a steady pressure within the range 1000 to 2000 pounds per sq. inch and to a steady temperature dependent on the pressure employed. A pressure of 1000 pounds per sq. inch may be applied for 6¢ minutes at a temperature of 122‹ C. or with an applied pressure of 2000 pounds per sq. inch and temperature of 112‹ C. the time of application should be at least 9 minutes. The coated base-plate prior to its combined pressure and heat treatment may be subjected to a preliminary heating without applied pressure, as described in Specification 560,565, at a temperature above 80‹ C., but below the melting point of the selenium, for example at 217‹ C. for 2 minutes. The selenium element is completed by a further period of heating at a temperature just below the melting point followed by an electrical " forming " treatment after the counterelectrode has'been applied to the surface of the selenium. Specification 509,432 and the Journal of the Institution of Electrical Engineers for May, 1941, also are referred to.