Effect of the electric field in the space-charge layer on the efficiency of short-wave photoelectric conversion in GaAs Schottky diodes

A study is reported of the quantum efficiency of the short-wave photoelectric effect as function of the reverse bias applied to GaAs Schottky diodes when the light absorption length is much shorter than the width of the space charge region. The quantum efficiency of photoelectric conversion is found to depend strongly on the contact electric field and the photon energy. The field independence of the quantum efficiency is interpreted in terms of a fluctuational trap model. The model can also be used to determine the loss factor for hot photocarriers, which is found to increase in a stepwise manner with increasing photon energy. This effect is explained in terms of the formation of excitons in X-and L-valleys of the semiconductor. Fiz. Tekh. Poluprovodn. 31, 1225–1229 (October 1997)