Use of the GaAs and GaP films with anomalous photovoltage for X-ray detection

The possibility of application of films made of A3B5-type (GaAs and GaP) semiconductor compounds to x-ray detection is studied. The GaAs and GaP films are prepared by evaporation of monocrystals of the initial material in vacuum (10-4-10-5 Pa) onto a 10x10x1 mm glass substrate. Films 0.1-0.2 μm thick have 1010-1014 Ohm dark resistance and after white lighting at the intensity of 0.1 W/cm2 400-500 V photovoltage per 1 cm length is generated. The conclusion is made that in contrast to CdTe ad Sb2Se3 films sensitive to x-rays only in air, GaAs and GaP films are sensitive to x rays both in air and in vacuum