Research on Antimony-Cesium Photocathode Based on Tungsten Substrate

In order to satisfice the needs of photocathodes working in microwave vacuum devices with stability and high quantum efficiency, in this paper, we developed a new method to manuscript photocathode by evaporating cesium source in a vacuum chamber. Through a diffusion tungsten layer, the steam of alkali evaporation would be more uniformly when deposited on the substrates which is pressed by tungsten and antimony metal powder. The photocathode was driven by a diode-pump solid state laser with 532 nm wavelength, eventually we obtained a stable quantum efficiency of 2.1×10−5• In order to make the ratio of antimony cesium on the surface of the substrate more suitable, we could change the ratio of tungsten and antimony. Besides, using nano-tungsten as the substrate is expected to obtain a better quantum efficiency. This research provides a new method to fabricate photocathode.