Intrinsic p-type W-based transition metal dichalcogenide by substitutional Ta-doping

TL;DR

This paper demonstrates a method to produce intrinsic p-type W-based transition metal dichalcogenides through substitutional Ta-doping, enabling high-performance electronic and optoelectronic devices with nearly ideal diode behavior.

Contribution

It introduces an experimental approach for intrinsic p-type W-based TMDs via substitutional Ta-doping, overcoming previous challenges in the field.

Findings

Ta-doped WSe2 FETs show ~10^6 on/off ratio at room temperature.

High-quality vdW p-n heterojunctions exhibit near-ideal diode characteristics.

Devices demonstrate excellent photodetecting performance.

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have recently emerged as promising candidates for future electronics and optoelectronics. While most of TMDs are intrinsic n-type semiconductors due to electron donating which originates from chalcogen vacancies, obtaining intrinsic high-quality p-type semiconducting TMDs has been challenging. Here, we report an experimental approach to obtain intrinsic p-type Tungsten (W)-based TMDs by substitutional Ta-doping. The obtained few-layer Ta-doped WSe2 (Ta0.01W0.99Se2) field-effect transistor (FET) devices exhibit competitive p-type performances, including ~10^6 current on/off at room temperature. We also demonstrate high quality van der Waals (vdW) p-n heterojunctions based on Ta0.01W0.99Se2/MoS2 structure, which exhibit nearly ideal diode characteristics (with an ideality factor approaching 1 and a rectification ratio up to 10^5) and excellent photodetecting performance. Our study suggests that substitutional Ta-doping holds great promise to realize intrinsic p-type W-based TMDs for future electronic and photonic applications.