Electrical properties of n-n ZnSe/GaAs heterojunctions

ZnSe/GaAs n-n heterojunctions were prepared by heteroepitaxial growth of ZnSe on GaAs from the vapor phase. The electrical properties of the heterojunctions were found to be strongly dependent on the ZnSe resistivity. Heterojunctions with semi-insulating (10 9 –10 11 Ω cm) ZnSe showed symmetric current density versus voltage ( J-V ) characteristics and a voltage-independent capacitance. Rectification was shown by n-n heterojunctions prepared with conductive (5–25 Ω cm) ZnSe. J-V and capacitance versus voltage measurements indicated that the n-n structure behaves like a lattice-matched Schottky barrier with a barrier height of 0.7 eV. These findings were compared with recent theoretical models of the electronic structure of the ZnSe/GaAs interface.