Self-Driven High-Performance Gate-Voltage-Tunable and Enhanced Performance Optoelectronic Device Based on FePS₃/MoS₂ Heterojunctions

Abstract

The van der Waals heterojunctions are crucial for the development of next-generation high-performance optoelectronic devices due to their high-quality interface. In this study, FePS₃/MoS₂ van der Waals heterojunctions were fabricated, and their electronic and optoelectronic properties were investigated. The devices demonstrated typical rectification behavior, characterized by a low rectification ratio and electron-dominated conductivity. The suppression of electron recombination was achieved by eliminating non-heterojunction regions on the FePS₃ side, leading to enhanced device performance. Notably, a large rectification ratio of 6.3 × 10⁴ and an ideality factor of 1.24 were observed. Furthermore, the devices also exhibited self-driven photodetection performance, including a responsivity of 203 mA/W, a high-speed response/recovery time of 70.4/92 μs, and a high on/off ratio of 5.4 × 10³. Responsivity and on/off ratio were further improved to higher values of 1.4 A/W and 1.2 × 10⁵ by the modulation of V_g. The results offer valuable insights for improving and developing high-performance devices based on two-dimensional materials and heterojunctions.