Semiconductor photocathode for near-infrared radiation - comprising transparent gallium-aluminium arsenide layer and electron-emitting gallium-indium arsenide layer

摘要

Photocathode for near-infrared radiation comprises a relatively thick substrate (10-500 mu) having the general formula Ga1-yAlyAs (0.4 y 1) and a thin layer 0.5-10 mu) epitaxially grown on the substrate consisting of a p-doped cpd. having the formula Ga1-xInxAs (0 x 0.5), which is pref. coated with a mono-atomic layer of an alkali metal or its cpd. to facilitate electron emission. The substrate is sufficiently thick to ensure mechanical strength. On the other hand, the substrate transmits a considerable part of photons falling thereon so that a sufficiently copious electron emission takes place.