Single-Layer MoS₂Phototransistors

TLDR

The study develops a mechanically exfoliated single‑layer MoS₂ phototransistor to investigate light‑induced electrical properties and to explore its potential for multifunctional optoelectronic devices. The device, fabricated from a single‑layer MoS₂ nanosheet, shows photocurrent that depends solely on the incident optical power at a fixed drain or gate voltage. The phototransistor achieves complete photocurrent switching within ~50 ms, remains stable, and delivers higher photoresponsivity than comparable graphene‑based devices.

Abstract

A new phototransistor based on the mechanically exfoliated single-layer MoS2 nanosheet is fabricated, and its light-induced electric properties are investigated in detail. Photocurrent generated from the phototransistor is solely determined by the illuminated optical power at a constant drain or gate voltage. The switching behavior of photocurrent generation and annihilation can be completely finished within ca. 50 ms, and it shows good stability. Especially, the single-layer MoS2 phototransistor exhibits a better photoresponsivity as compared with the graphene-based device. The unique characteristics of incident-light control, prompt photoswitching, and good photoresponsivity from the MoS2 phototransistor pave an avenue to develop the single-layer semiconducting materials for multifunctional optoelectronic device applications in the future.