| 摘要 |
<p>1,107,445. Selenium rectifiers. SIEMENSSCHUCKERTWERKE A.G. 28 April, 1966 [28 April, 1965], No. 18791/66. Heading H1K. In a selenium rectifier the counter-electrode and the selenium layer contain thallium in a concentration ratio of from 1 : 100 to 1 : 10 by weight. The thallium in the counter electrode prevents the migration of the thallium from the selenium layer during manufacture and use. As shown, a rectifier is produced by dusting the surface of a nickel-coated aluminium plate 1 with powdered selenium heating to form a nickel selenide layer 2, evaporating-on a selenium layer 3 containing chlorine and tellurium, pre-crystallizing this layer by tempering, evaporating on a thin selenium layer 4 containing iodine and 200 to 2000 p.p.m. thallium, and spraying-on a counter-electrode 5 of 32/68 cadmium/tin alloy containing 10 to 100 p.p.m. thallium so that the concentration ratio of the thallium in the counter electrode 5 and the selenium layer 4 is 1 : 20. The device is heated to just below the melting-point of selenium to convert the selenium into the hexagonal form and to form a layer of cadmium selenide between layers 4 and 5. The device is then electrically formed. It is stated that it is known to include thallium in the counter-electrode and in the selenium layer in a concentration ratio of about 1 : 2.5.</p> |
