Continuous Large Area Few Layers MoS2 Films by Pulsed Laser Deposition and Effect of Annealing in Sulfur Environment

The superior optical and electrical properties of mono and few layers transition metal dichalcogenides, particularly molybdenum disulfide (MoS2), makes it a promising candidate for next generation practical flexible nanoelectronics and optoelectronics devices. However, controlled growth, scalability, uniform and continuous large area with repeatable synthesis of mono and few layers MoS2 is still a major concern. In this study, a two-step synthetic approach has been adopted for the preparation of few layers MoS2 films. MoS2 films were prepared with different deposition times (45 s, 75 s, 100 s, 2.5 min and 10 min) at a same laser power, 200 mJ/cm(2) by pulsed laser deposition on sapphire substrate, which were further annealed at 850 degrees C in sulfur-rich environment. The optical properties of the annealed samples were moderately improved. Significantly, MoS2 film deposited at 45 s exhibited a superior photoluminescence response with full width half maximum value of similar to 72.24 meV, as compared to previous report of few layers MoS2 by physical vapor deposition. Moreover, Raman frequency difference between A(1g) and E-2g(1) was found to be 23.6 cm(-1).