Measurements of transient photocapacitance and photocurrent on MOVPE-grown Au/ZnSe/GaAs heterostructures

The results of transient photocapacitance and photocurrent measurements performed on MOVPE-grown Au/ZnSe/GaAs heterostructures are reported for different photon energies and intensities of the monochromatic radiation. Thresholds in both spectra are observed at 1.4 eV. We attribute the photocapacitance and the photocurrent to the generation of electron-hole pairs in GaAs followed by trapping of the holes on interface states at the heterojunction between ZnSe and GaAs. In our interpretation, the stationary photocurrent is due to recombination of the trapped holes with electrons of the ZnSe conduction band. (C) 1998 Elsevier Science B.V. All rights reserved.