Photoluminescence quenching of CVD grown WS2 monolayers treated with low-power Ar plasma

Defect engineering in two-dimensional materials is of high importance to improve a specific property of such materials. By introducing defects directly in the lattice, by means of ion doping or vacancies, it is possible to optimize the structure for a target application, such as high-performance batteries, catalysis, or optoelectronics. Herein, monolayer WS2 was synthesized by chemical vapor deposition and was subsequently subjected to Ar plasma treatment. The changes in properties were monitored using Raman spectroscopy, photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. The influence of defects resulted in a variation in the intensity of the PL signal, as well as a progressive redshift owing to an increase in the defect density with increasing plasma treatment time, and through the analysis of the PL and Raman spectra one can quantify the evolution of defects in the WS2 monolayers due to the treatment.

Automated summary

Defect engineering plays a crucial role in improving specific properties of two-dimensional materials. This study synthesized monolayer WS2 using chemical vapor deposition and introduced defects through Ar plasma treatment. The changes in properties were analyzed using various spectroscopy techniques, revealing the influence of defects on photoluminescence signal and providing a quantitative analysis of defect evolution in WS2 monolayers.