Significant Suppression of Dark Current in a Surface Acoustic Wave Assisted MoS2 Photodetector

Abstract

Abstract 2D materials are considered as potential candidates for the next generation of optoelectronic materials. However, their optical absorption is typically weak due to thickness limitations, greatly restricting the photodetection capabilities of devices. To enhance the photoelectric gain of 2D materials or devices and improve detection sensitivity, various modulation methods such as strain, electric field, and magnetic field are commonly introduced. Among them, surface acoustic wave (SAW) represents a unique and effective modulation approach. In this study, photodetectors are fabricated based on few‐layer MoS2 on a SAW delay line on a LiTaO3 substrate. The interaction between SAW and MoS2 successfully manipulates the optoelectronic performance of the MoS2‐based devices. Under the influence of SAW, the dark current of the devices is significantly reduced by more than two orders of magnitude, while the photocurrent remains almost unchanged, resulting in excellent photoresponse performance. The devices provide a promising pathway for high‐performance optoelectronic applications and reveal a new possibility for acoustic devices in optoelectronics.

Keywords

• 2D materials
• dark current
• high sensitivity
• photodetectors
• surface acoustic waves