Highly Sensitive, Ultrafast, and Broadband Photo‐Detecting Field‐Effect Transistor with Transition‐Metal Dichalcogenide van der Waals Heterostructures of MoTe₂ and PdSe₂

Abstract

Recently, van der Waals heterostructures (vdWHs) based on transition‐metal dichalcogenides (TMDs) have attracted significant attention owing to their superior capabilities and multiple functionalities. Herein, a novel vdWH field‐effect transistor (FET) composed of molybdenum ditelluride (MoTe2) and palladium diselenide (PdSe2) is studied for highly sensitive photodetection performance in the broad visible and near‐infrared (VNIR) region. A high rectification ratio of 6.3 × 105 is obtained, stemming from the sharp interface and low Schottky barriers of the MoTe2/PdSe2 vdWHs. It is also successfully demonstrated that the vdWH FET exhibits highly sensitive photo‐detecting abilities, such as noticeably high photoresponsivity (1.24 × 105 A W−1), specific detectivity (2.42 × 1014 Jones), and good external quantum efficiency (3.5 × 106), not only due to the intra‐TMD band‐to‐band transition but also due to the inter‐TMD charge transfer (CT) transition. Further, rapid rise (16.1 µs) and decay (31.1 µs) times are obtained under incident light with a wavelength of 2000 nm due to the CT transition, representing an outcome one order of magnitude faster than values currently in the literature. Such TMD‐based vdWH FETs would improve the photo‐gating characteristics and provide a platform for the realization of a highly sensitive photodetector in the broad VNIR region.

High-Performance Photodetectors with an Ultrahigh Photoswitching Ratio and a Very Fast Response Speed in Self-Powered Cu2ZnSnS4/CdS PN Heterojunctions

“…14−17 In addition, the existence of the ineluctable defects for the compound semiconductors affects and even determines the processes including carrier generation, excitation, relaxation, transfer, and recombination. 18,19 However, to the best of our best knowledge, photoresponse properties related to the defects in CZTS film photodetectors have not been well-documented and the possible physics mechanism is still unexplored. In this work, self-powered photodetectors with a PN heterojunction of CZTS and CdS layers have been fabricated.…”

Atomic Layer MoTe2 Field-Effect Transistors and Monolithic Logic Circuits Configured by Scanning Laser Annealing

“…As shown in Figure d, the methods for realizing n-type MoTe 2 FETs reported to date include intrinsic n-type MoTe 2 , chemical doping, surface charge transfer doping (SCTD), and contact engineering . Our n-type MoTe 2 FETs exhibit higher mobility than counterparts reported in previous studies. ,,− ,,,− In addition, MoTe 2 FETs with fewer numbers of layers (<12 layers) exhibit declined mobility due to enhanced Coulomb impurity scattering …”

Type‐II van der Waals Heterostructures Based on AsP and Transition Metal Dichalcogenides: Great Promise for Applications in Solar Cell

“…The broad application prospects are wide in many fields, such as photoelectric devices and photoelectric detection. [30][31][32][33] Numerous previous studies on TMD-based heterostructures are related to type-II band alignment. [34][35][36] In 2 Se 3 /MoS 2 vdW heterostructure has a remarkable out-of-plane piezoelectric performance, a high positive value of the piezoelectric coefficient d 33 , and excellent piezoelectric properties resulting from the type-II band alignment.…”