| 摘要 |
544,733. Photo sensitive electrode materials. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Feb. 27, 1941, No. 2689. Convention date, Feb. 27, 1940. Drawings to Specification. [Class 39 (i)] The base metal, preferably silver, of a photosensitive electrode is subjected to the action of mercury to form an amalgam, which is then heated to drive off the mercury and sensitized. This process produces voids and fissures in the base metal, which reduces secondary emission and light reflection ; the response to red light is also reduced. In one form, a mosaic deposited on a sheet of mica, with or without a thin intervening film of cryolite, is supported over a beaker containing a few drops of mercury, which is heated to form vapour which amalgamates with the mosaic. Subsequent heating for one minute at 600‹ C. drives off the mercury. If the electrode is continuous, the mercury may be applied by dipping or by electrodeposition. In sensitizing the apparatus is baked at 390-410‹ C. until a residual pressure of one micron is reached and for a further five minutes. A glow discharge in oxygen, first at 1.2 mm. pressure and then at 1.8 mm. pressure oxidizes the silver to a bright red. Caesium is introduced and the excess removed by baking at 263-285‹ C. until the cathode turns straw colour. |
