The lateral photovoltaic effect of WSeS/Si heterojunctions

Two-dimensional transition metal dichalcogenides (2D TMDs) have garnered considerable interest for next-generation photodetectors, owing to their remarkable electrical and optoelectronic characteristics. This work systematically investigates the lateral photovoltaic characteristics of the WSeS/Si heterojunction. X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy confirm that the WSeS thin films prepared via pulsed laser deposition (PLD) possess excellent crystalline quality. At room temperature, the WSeS/n-Si (84 mV mm⁻¹) and WSeS/p-Si (106 mV mm⁻¹) heterojunctions exhibit strong position sensitivity under 532 nm illumination, with relaxation times of 0.22 and 0.41 µs, respectively. Furthermore, the laser response characteristics of the lateral photovoltaic effect under high-intensity illumination can effectively prevent the failure of two-dimensional material optoelectronic devices under high-intensity light. These results confirm the significant potential of the WSeS/Si heterojunction photodetectors for self-powered position-sensitive detection.