Synthesis of mono/ few layered MoS2 thin films and graphene: MoS2 van der Waal heterostructures using pulsed laser deposition

Molybdenum disulpihde mono/few layers were deposited by pulsed laser deposition on graphene substrates thereby forming MoS₂ - graphene van der Waal heterostructures. Initially, the optimization of the growth MoS₂ layers were carried out on thermal oxide silicon (Si/SiO₂) substrate by pulsed laser deposition technique. The difference between two Raman peaks A_1g and E1/2_g modes (▵ƒ) was used to determine the number of layers of the grown MoS₂ thin films. The photoluminescence spectra with two excitonic peaks A and B confirmed the formation of mono/ few layered MoS₂ thin films. Similar growth conditions were used to deposit MoS₂ thin films on CVD grown graphene transferred on to thermally oxidized silicon substrate. The formation of MoS₂ - graphene van der Waal heterostructures were confirmed using Raman analysis.