Properties of ZnO thin films grown on Si substrates by MOCVD and ZnO/Si heterojunctions

Undoped n-ZnO thin films were successfully grown on p-Si (100) substrates by low-pressure metalorganic chemical vapour deposition (MOCVD). The c-axis oriented ZnO films were grown on Si at different temperatures using diethylzinc (DEZn) and oxygen (O-2). The structural and optical properties of ZnO films were investigated using x-ray diffraction (XRD) and photoluminescence (PL) spectra, respectively. It is found that the ZnO film grown at 610 C shows the best crystallinity and optical quality. Current-voltage (I-V) characteristics of all n-ZnO/p-Si heterojunctions exhibit nonlinear and rectifying characteristics with a small current leakage in the reverse direction. Junction leakage of the heterojunction deposited at 620 degrees C is higher than those of the other heterojunctions.