Large Lateral Photovoltaic Effect and Spatial Resistance Effect on MoS₂/p-Si Interface

An in-depth study of new phenomena emerging from the interaction between light and matter is a vital scientific research effort. In this report, we investigate the lateral photovoltaics and spatial resistance on p-Si surfaces under 520 nm laser stimulation. Because of the surface states of p-Si, the lateral photovoltage sensitivity can reach 286 mV/mm, and the spatial resistance change ratio can reach 1059%. Then, we modulate these two effects by growing three different morphologies of MoS2 on the Si surface. Due to the photosensitive properties of MoS2 nanoparticles, the lateral photovoltage sensitivity can be enhanced up to 368 mV/mm, while the spatial resistance change ratio can reach 2202%. In this process, we observe a new phenomenon that the p-Si surface modified by MoS2 no longer shows the traditional bipolar-resistance effect, and the laser position corresponding to the minimum resistance has been shifted. Based on this finding, we refine the previously proposed bipolar-resistance effect theory and confirm our findings through theoretical calculations. Our modulation strategy can realize both photovoltage-based detection and photoconductivity-based detection, which provides a reliable reference for the study of photoelectric devices.