Controllable p-type Doping of 2D WSe2 via Vanadium Substitution

TL;DR

This paper demonstrates a scalable method for p-type doping of 2D WSe2 using vanadium substitution, enabling precise impurity control for electronic applications.

Contribution

It introduces a scalable growth process for vanadium-doped WSe2 and confirms the substitutional doping mechanism through experimental and theoretical analysis.

Findings

Vanadium substitutes tungsten in WSe2, creating p-type doping.

Doping is effective at 800°C and 400°C, compatible with device fabrication.

Field-effect transistors show dominant hole conduction with increased V doping.

Abstract

Scalable substitutional doping of two-dimensional (2D) transition metal dichalcogenides (TMDCs) is a prerequisite to developing next-generation logic and memory devices based on 2D materials. To date, doping efforts are still nascent. Here, we report scalable growth and vanadium (V) doping of 2D WSe2 at front-end-of-line (FEOL) and back-end-of-line (BEOL) compatible temperatures of 800 {\deg}C and 400 {\deg}C, respectively. A combination of experimental and theoretical studies confirm that vanadium atoms substitutionally replace tungsten in WSe2, which results in p-type doping via the introduction of discrete defect levels that lie close to the valence band maxima. The p-type nature of the V dopants is further verified by constructed field-effect transistors, where hole conduction becomes dominant with increasing vanadium concentration. Hence, our study presents a method to precisely control the density of intentionally introduced impurities, which is indispensable in the production of electronic-grade wafer-scale extrinsic 2D semiconductors.