Schottky diode photocurrent in the intrinsic-absorption region

The spectral and field characteristics of photocurrent in Au-GaAs Schottky diodes were measured over the energy range of 1.30 to 2.85 eV at 300K. It proved possible to regulate the contribution of surface recombination and space-charge region recombination to photocurrent losses by varying the diode quality parameter, the diffusion length of minority carriers, and the concentration of shallow donor levels. It is shown that the influence of surface recombination is enhanced by diffusion of majority carriers from the bulk region. Buildup of minority carriers at the metal-semiconductor junction increases the field dependence of photocurrent, while space-charge region recombination affects the spectral characteristics of the photocurrent.