A strain tunable single-layer MoS2 photodetector

TL;DR

This paper demonstrates that applying biaxial strain to single-layer MoS2 photodetectors significantly enhances their photoresponsivity, response time, and spectral bandwidth, enabling tunable optoelectronic properties for flexible devices.

Contribution

It introduces a method to tune the optical and electrical performance of MoS2 photodetectors through strain engineering, showing substantial improvements over unstrained devices.

Findings

Photoresponsivity increased by 2-3 orders of magnitude

Response time varied from <80 ms to 1.5 s

Spectral bandwidth tunable with a gauge factor of 135 meV/%

Abstract

Strain engineering, which aims to tune the bandgap of a semiconductor by the application of strain, has emerged as an interesting way to control the electrical and optical properties of two-dimensional (2D) materials. Apart from the changes in the intrinsic properties of 2D materials, the application of strain can be also used to modify the characteristics of devices based on them. In this work, we study flexible and transparent photodetectors based on single-layer MoS2 under the application of biaxial strain. We find that by controlling the level of strain, we can tune the photoresponsivity (by 2-3 orders of magnitude), the response time (from <80 ms to 1.5 s) and the spectral bandwidth (with a gauge factor of 135 meV/% or 58 nm/%) of the device.