Repairing atomic vacancies in single-layer MoSe2 field-effect transistor and its defect dynamics

TL;DR

This study demonstrates a method to repair atomic vacancies in single-layer MoSe2 FETs using EDTA processing, significantly enhancing carrier mobility and elucidating defect dynamics through combined experimental and theoretical approaches.

Contribution

It introduces a novel EDTA-based repair technique for atomic vacancies in MoSe2 and provides detailed insights into defect dynamics using multiple advanced characterization methods.

Findings

Carrier mobility increased from 0.1 to over 70 cm²/Vs.

Atomic vacancies are repaired, reducing mid-gap impurity states.

Raman spectra show a 1.5 cm⁻¹ red shift indicating defect repair.

Abstract

Here we repair the single-layer MoSe2 field-effect transistors by the EDTA processing, after which the devices' room-temperature carrier mobility increases from 0.1 to over 70cm2/Vs. The atomic dynamics is constructed by the combined study of the first-principle calculation, aberration-corrected transmission electron microscopy and Raman spectroscopy. Single/double Se vacancies are revealed originally, which cause some mid-gap impurity states and localize the device carriers. They are found repaired with the result of improved electronic transport. Such a picture is confirmed by a 1.5cm-1 red shift in the Raman spectra.