Heat annealing influences the optical properties of 2D-MoS2 nanoparticles

Abstract

Numerous structural defects, such as vacancies, dislocations, admixtures, grain boundaries and edges in the 2 D-MoS2 particles change their optical, mechanical, and electrical properties that influences their application. Here we investigate the heat annealing of MoS2 particles at 700 °C in an argon atmosphere, and demonstrate the appearance of sulfur vacancies in them using FTIR spectroscopy. The new IR absorption bands belonging to deformation and stretching vibrations of anions centered at 614 cm−1 and 1115 cm−1, respectively, were registered after annealing. In both MoS2 samples, those before and after the heat annealing, the Mo-Ox vibrations were registered by FTIR and Raman spectroscopy. Negligible changes observed in the Raman spectra of the title compound are discussed.