Influence of electric field in a space charge layer on the short-wave photoeffect quantum efficiency in GaAs Schottky diodes

The short-wave photoeffect quantum efficiency dependence on the reverse bias has been studied experimentally in GaAs Schottky diodes. The light absorption length was much less that the space charge layer width. A strong dependence of the quantum efficiency on the contact electric field was found. The field dependence of the quantum efficiency was explained within the frame of a fluctuation traps model. The model also allowed us to define a coefficient of hot photo-carriers losses. The increase of the coefficient with the photon energy has a stepwise character. This effect is explained in terms of exciton formation in X and L semiconductor valleys