Abstract
•Conventional ZnO-based MSM-PD suffers from low responsivity and speed limitations.•Use of Heterojunctions (HJ) enhances the response speed of the ZnO based MSM-PD.•Numerical simulation is used to study the performance of a ZnO/Si HJ based MSM-PD.•The results revealed the presence of a hole accumulation at the Si side of the HJ.•The hole accumulation has profound effects on the MSM-PD’s characteristics.
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 μm finger spacing and a 1 μm ZnO active-layer thickness yielded excellent temporal-response characteristics and excellent noise-rejection ability.