Atomically thin Schottky junction with a gap-mode plasmon for enhanced photoresponsivity in MoS2-based photodetectors. (26th January 2021)

• Record Type: Journal Article
• Authors: Jin, Hyeok Jun; Lee, Khang June; Park, Cheol Min; Shin, Gwang Hyuk; Hong, Woonggi; Oh, Dongsik; Choi, Sung-Yool
• Is Part Of: Journal of physics. Volume 54:Number 14(2021)
• Publication Date: 2021-01-26
• Subjects: atomically thin Schottky junction -- gap-mode plasmons -- MoS2 -- photodetectors -- ultrahigh photoresponsivity; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/abd6ac
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Two-dimensional (2D) materials present various extraordinary properties that are advantageous in optoelectronic devices with atomically thin nature. Despite their excellent light–matter interaction, a low optical absorption that is proportional to thickness is considered to be a major limitation. In this study, a gap-mode plasmon structure is applied to the Schottky junction of Au–MoS2 to compensate for its low absorption. The magnitude of the gap-mode plasmon is generally known to be inversely proportional to the gap distance between two metal nanostructures; hence, an atomically thin 2D material can be considered to be a good candidate for a gap spacer. Owing to the gap-mode plasmon structure, the photoresponsivity of the proposed device is enhanced by approximately 11.6 times from 25 to 290 A W −1 under 1 nW of laser power, without photoresponse time degradation. Two operation modes, named the photovoltaic and the photoconductive mode, are also observed through different response times; these present different carrier transport mechanisms depending on the existence of bias voltage.