Atomic Layer Depositon of Al2O3 on MoS2 for Recovery Enhanced Gas Sensor

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDs) which possess large surface-to-volume ratio have been widely used for room temperature gas sensing applications. [1] However, due to its intrinsic defect or vacancies on TMD surface, incomplete recovery of TMD gas sensors hinder the realization of reliable and repeatable use of 2D TMD gas sensors. [2] Here, we demonstrate improvement of recovery rate of TMD gas sensors by covering TMD surfaces’ defect or vacancies with Al2O3 using atomic layer deposition. Raman, AFM, XPS data have been showed. Especially, SEM data have showed that Al2O3 is partially covered on grain boundaries or defects of MoS2 which is favorable for enhancing recovery performance of TMD gas sensors. The pristine MoS2 gas sensors show 74 % of recovery rate in the case of NO2 sensing. However, the recovery rate of the Al2O3 functionalized MoS2 gas sensors improved up to 96 %. Our proposed method shows promising strategy for improving recovery rate of 2D TMD gas sensors.