Detecting the Repair of Sulfur Vacancies in CVD-Grown MoS2 Domains via Hydrogen Etching

Inherent sulfur vacancies in molybdenum disulfide (MoS2) films grown via chemical vapor deposition have restricted the practical application of MoS2 in optoelectronic devices. The repair of sulfur vacancies is important for improving the quality of MoS2 and enhancing the performance of devices based on MoS2 films. Here we report a route that uses hydrogen (H2) etching to detect the repair effect of sulfur vacancies. The domains with and without sulfur annealing were etched via H2 under the same conditions, and the changes of surface microstructures and properties were compared. It was found that the tolerance of MoS2 to H2 etching was enhanced after sulfur annealing. Results of the photoluminescence spectrum further proved that H2 etching could effectively detect the repair effect of sulfur vacancies. As a practical application, the optimum condition of sulfur annealing was obtained through H2 etching. Our work promotes the practical application of MoS2 in the field of new-generation electronics and optoelectronics.