Detection of cyclotron resonance using photo-induced thermionic emission at graphene/MoS2 van der Waals interface

TL;DR

This paper introduces a novel infrared detection method for cyclotron resonance in graphene using photo-induced thermionic emission at a graphene/MoS2 interface, achieving high sensitivity and potential for advanced photodetectors.

Contribution

The study presents a new out-of-plane transport detection technique for cyclotron resonance at a vdW interface, with significantly improved sensitivity over previous in-plane methods.

Findings

High sensitivity of about 10^6 V/W achieved

Detection method based on electron-hole separation at the vdW junction

Potential for high-performance infrared photodetectors

Abstract

We demonstrate the detection of cyclotron resonance in graphene by using a photo-induced thermionic emission mechanism at the graphene/MoS2 van der Waals (vdW) Schottky junction. At cyclotron resonance in Landau-quantized graphene, the infrared light is absorbed and an electron-hole pair is generated. When the energy of a photoexcited electron exceeds the band offset energy at the graphene/MoS2 interface, the electron transfer occurs from graphene to the conduction band of MoS2, and the hole remains in graphene. This creates an electron-hole separation at the graphene/MoS2 interface at cyclotron resonance and a photovoltage is generated. The proposed method is an infrared photodetection technique through out-of-plane transport at the vdW junction, which is distinct from the previously reported methods that use in-plane transport in graphene for electronic detection of the cyclotron resonance. Despite the simple structure of our device with a single-vdW junction, our method exhibits a very high sensitivity of about 10^6 V/W, which shows an improvement of three orders of magnitude over the previously reported values. Therefore, the proposed method displays a high potential for cyclotron resonance-based infrared photodetector applications.