Current transport mechanism of atomic layer deposited ZnO on 3C–SiC/p-Si heterostructure

The atomic layer deposition (ALD) growth of ZnO on n-SiC/p-Si heterojunction was carried out and the current transport mechanism of ZnO/n-SiC/p-Si heterojunction was investigated. The current–voltage (I–V) characteristics for n-SiC/p-Si heterojunction showed the normal p-n junction properties, which became reversal for n-ZnO/n-SiC/p-Si heterojunction. The Arrhenius plots of reverse currents versus 1/kT produced the activation energies of 0.42 and 0.21 eV for n-SiC/p-Si and n-ZnO/n-SiC/p-Si heterojunctions, respectively. The decrease of current values with the temperature for n-ZnO/n-SiC/p-Si heterojunction would be due to the interface states near the ZnO/SiC interface. Capacitance–voltage (C–V) characteristics revealed the higher interface state density for n-ZnO/n-SiC/p-Si heterojunction.