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

Rectifying undoped and nitrogen-doped ZnOp-Si heterojunctions were fabricated by plasma immersion ion implantation and deposition. The undoped and nitrogen-doped ZnO films were n type (n∼ 1019 cm-3) and highly resistive (resistivity ∼ 105 Ω cm), respectively. While forward biasing the undoped- ZnOp-Si, the current follows Ohmic behavior if the applied bias Vforward is larger than ∼0.4 V. However, for the nitrogen-doped- ZnOp-Si sample, the current is Ohmic for Vforward 2.5 V. The transport properties of the undoped- ZnOp-Si and the N-doped- ZnOp-Si diodes were explained in terms of the Anderson model and the space charge limited current model, respectively. © 2006 American Institute of Physics.