High-Performance Infrared Photodetectors Based on 2D InSe

Abstract

2D InSe is one of the semimetal chalcogenides that has been recently given attention thanks to its excellent electrical properties, such as high mobility near 1000 cm2 V−1 s−1 and moderate band gap of ≈1.26 eV suitable for IR detection. In this talk, I will introduce our novel IR photodetectors using surface-doped InSe as a channel and multilayer graphenes as electrodes. IR photodetectors have been receiving increasing attention due to their applications in self-driving cars, networking IoT devices, biosensing, etc. A few top layers of InSe are p-doped using AuCl3, an electron absorbing material. Our surface-doped InSe photodetectors show outstanding performance, achieving a photoresponsivity (R) of ≈19,300 A W−1 and a detectivity (D*) of ≈3 × 1013 Jones at λ = 470 nm, and R of ≈7870 A W−1 and D* of ≈1.5 × 1013 Jones at λ = 980 nm, superior to previously reported 2D material based IR photodetectors. A detailed analysis regarding the impact of doping, an electrode type, the structure of graphene electrodes, and the encapsulation using hBN dielectric on the electrical and photoelectrical properties will be presented. I will also briefly talk about our newly demonstrated high-performance self-driven photodetectors as well.