Chemical Composition and Electronic Transport Properties of Na2KSb, Cs Thin Films.

This article is focused on photoelectric alkali-antimonide thin films exhibiting photoelectric sensitivity higher than 500 mu A multiplied by (times) lm** minus **1. The bulk composition is studied with optical tools such as spectral reflectance and transmittance. The effects of mixing or superposition of Na//3Sb and Na//2KSb phases upon photoemission properties are considered. The surfaces of Na//2KSb and Na//2KSb,Cs films are analyzed by Auger electron spectroscopy. The effect of chemical binding nature taking place between alkali and antimony atoms upon photoemissivity is outlined. The photoelectron escape depths are determined over the visible spectrum. Finally some concluding remarks are drawn out for night vision applications.