| 摘要 |
<p>470,552. Light-sensitive cells. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. Dec. 18, 1936, No. 34881. Convention date, Dec. 21, 1935. [Class 40 (iii)] [Also in Group XXXVI] A selenium electrode for a system with asymmetrical conductivity, e.g. a dry rectifier, is made by first subjecting commercial selenium to a purification process whereby any admixtures are rendered inactive or removed, then adding one or more substances to the selenium to increase its conductivity, and finally, after applying the selenium to a support, heating to convert the selenium to the conductive crystalline form. In one example, commercial selenium is purified by distillation, and 1 per cent bismuth iodide is added to the purified selenium in the molten condition. The product is then painted on an amalgamated brass support and heated to 200‹ C. for 24 hours or longer. An insulating coating preferably polystyrene, may then be added from a solution in benzene, followed.by the application of a drop of Wood's metal to form the counter-electrode. In another example, a current of air is passed through molten selenium whereby any admixtures present are rendered inactive, probably by oxidation ; calcium tungstate is then added and the selenium is applied to a support and heated. Reference has been directed by the Comptroller to Specification 317,010, [Class 37].</p> |
