Theoretical study and design of n-ZnO/p-Si heterojunction MSM photodiode for optimized performance

摘要

The effects of using p-Si as a substrate on the performance of a thin-film ZnO-based metal-semiconductor-metal photodetector were examined theoretically via a two-dimensional numerical simulation. This study aimed at attaining a comprehensive understanding of carrier dynamics, leading to the optimization of the device structure for improved performance. The simulation indicated the presence of a hole accumulation at the heterojunction interface below the cathode contact. This layer plays a major role in the temporal-response characteristics of the device. The results indicate that a 1 mu m finger spacing and a 1 mu m ZnO active-layer thickness yielded excellent temporal-response characteristics and excellent noise-rejection ability.