A Versatile Post-Doping Towards Two-Dimensional Semiconductors

TL;DR

This paper presents a simple post-doping method for 2D TMD semiconductors using low-energy dopant beams and chalcogen flux, enabling controlled, substitutional doping with significant electronic property improvements.

Contribution

It introduces a novel, versatile post-doping technique for 2D TMDs using simultaneous low-energy dopant and chalcogen beams, allowing precise control and patterning.

Findings

Substitutional doping achieved with controlled dopant densities.

Doped WSe2 exhibits p-type behavior with over 100x increase in on current.

Position-selective doping demonstrated with patterned masks.

Abstract

We have developed a simple and straightforward way to realize controlled post-doping towards 2D transition metal dichalcogenides (TMDs). The key idea is to use low-kinetic energy dopant beams and a high-flux chalcogen beam at the same time, leading to substitutional doping with controlled dopant densities. Atomic-resolution transmission electron microscopy has revealed that dopant atoms injected toward TMDs are incorporated substitutionally into the hexagonal framework of TMDs. Electronic properties of doped TMDs (Nb-doped WSe2) have shown drastic change, p-type action with more than two orders of magnitude increase in on current. Position-selective doping has also been demonstrated by the post-doping toward TMDs with a patterned mask on the surface. The post-doping method developed in this work can be a versatile tool for 2D-based next-generation electronics in the future.