Highly Sensitive MoS2 Photodetectors with Graphene Contacts

TL;DR

This paper demonstrates scalable, large-area MoS2 photodetectors with graphene contacts that achieve record high detectivity, suitable for flexible electronics, overcoming limitations of previous small-scale, non-scalable fabrication methods.

Contribution

It introduces a scalable fabrication method for MoS2 photodetectors with graphene contacts, achieving record detectivity and enhanced flexibility for practical applications.

Findings

Record shot-noise-limited detectivity of 8.7 x 10^14 Jones in ambient conditions.

Large-area MoS2 grown by chemical vapor deposition is effective for high-performance photodetectors.

Graphene contacts enable tunable band alignment and improved device scalability.

Abstract

Two-dimensional materials such as graphene and transition metal dichalcogenides (TMDs) are ideal candidates to create ultra-thin electronics suitable for flexible substrates. Although optoelectronic devices based on TMDs have demonstrated remarkable performance, scalability is still a significant issue. Most devices are created using techniques that are not suitable for mass production, such as mechanical exfoliation of monolayer flakes and patterning by electron-beam lithography. Here we show that large-area MoS2 grown by chemical vapor deposition and patterned by photolithography yields highly sensitive photodetectors, with record shot-noise-limited detectivities of 8.7 X 10^14 Jones in ambient condition and even higher when sealed with a protective layer. These detectivity values are higher than the highest values reported for photodetectors based on exfoliated MoS2. We study MoS2 devices with gold electrodes and graphene electrodes. The devices with graphene electrodes have a tunable band alignment and are especially attractive for scalable ultra-thin flexible optoelectronics.