The preparation and study of the optical absorption edge of thin films of gallium arsenide

Films of gallium arsenide have been prepared by evaporation on to amorphous substrates. A simple and effective method of evaporating gallium arsenide, which would also be applicable to other III-V compounds, is described. The optical absorption edge has proved to be less steep in the films than expected from single crystal data, the absorption extending into the infrared, and is a function of substrate temperature.