Electrical Properties of Anisotype ZnO:Al/n-ZnSe/p-CdTe Heterostructures

ZnO:Al/n-ZnSe/p-CdTe anisotype heterostructures with diode properties were fabricated by the high-frequency magnetron deposition of ZnO:Al and n-ZnSe thin films onto the surface of crystalline p-CdTe. The flow of currents limited by the space charge at forward voltages up to 0.45 V and tunneling currents at V > 0.45 V was established. A change in these current flow mechanisms was observed at reverse voltages V = -0.6 V. The main part of the energy barrier qϕ_k = 1 eV of the ZnO:Al/n-ZnSe/p-CdTe heterostructure was formed in the p-CdTe substrate, which was established from studies of capacitance-voltage (C-V) characteristics. A model of the energy diagram of the heterostructure is proposed.