Current transport studies of ZnO/p-Si heterostructures grown by plasma immersion ion implantation and deposition

Rectifying undoped and nitrogen-doped ZnO/p-Si heterojunctions were fabricated by plasma immersion ion implantation and deposition. The undoped and nitrogen-doped ZnO films were n type (n similar to 10(19) cm(-3)) and highly resistive (resistivity similar to 10(5) Omega cm), respectively. While forward biasing the undoped-ZnO/p-Si, the current follows Ohmic behavior if the applied bias V-forward is larger than similar to 0.4 V. However, for the nitrogen-doped-ZnO/p-Si sample, the current is Ohmic for V-forward < 1.0 V and then transits to J similar to V-2 for V(forward >)2.5 V. The transport properties of the undoped-ZnO/p-Si and the N-doped-ZnO/p-Si diodes were explained in terms of the Anderson model and the space charge limited current model, respectively. (c) 2006 American Institute of Physics.