Evidence of strong effect from the interface on the electrical characteristics of ZnSe/GaAs heterojunctions

The interface properties of the molecular beam epitaxy (MBE)-grown ZnSe/GaAs system were investigated. A smooth reverse current-voltage (I-V) characteristic of the heterojunction and a slow increase in the current at constant reverse bias were observed. The slow capacitance transients are due to a change in the reverse bias. The slow relaxation induces a hysteresis in the I-V and capacitance-voltage (C-V) characteristics of the heterojunctions. A large frequency dispersion of the capacitance and a broad peak in the conductance spectra were observed at high temperature, which is due to the presence of a density of energy distributed interface states at the heterointerface.