High responsivity phototransistors based on few-layer ReS2 for weak signal detection

TL;DR

This paper demonstrates high-responsivity phototransistors based on few-layer ReS2, achieving record photoresponsivity and enabling detection of weak optical signals, highlighting ReS2's potential for sensitive optoelectronic devices.

Contribution

The study introduces a ReS2-based phototransistor with record high responsivity and demonstrates its capability for weak signal detection, surpassing previous two-dimensional material devices.

Findings

Maximum photoresponsivity of 88,600 A/W achieved

Record responsivity compared to similar 2D materials

Successful detection of weak light sources like a lighter

Abstract

Two-dimensional transition metal dichalcogenides are emerging with tremendous potential in many optoelectronic applications due to their strong light-matter interactions. To fully explore their potential in photoconductive detectors, high responsivity and weak signal detection are required. Here, we present high responsivity phototransistors based on few-layer rhenium disulfide (ReS2). Depending on the back gate voltage, source drain bias and incident optical light intensity, the maximum attainable photoresponsivity can reach as high as 88,600 A W-1, which is a record value compared to other two-dimensional materials with similar device structures and two orders of magnitude higher than that of monolayer MoS2. Such high photoresponsivity is attributed to the increased light absorption as well as the gain enhancement due to the existence of trap states in the few-layer ReS2 flakes. It further enables the detection of weak signals, as successfully demonstrated with weak light sources including a lighter and limited fluorescent lighting. Our studies underscore ReS2 as a promising material for future sensitive optoelectronic applications.