Experimental and theoretical investigation of 2d materials

In this thesis, a comprehensive study of monolayer MoS2 growth by Chemical Vapor Deposition (CVD) has been carried out and investigated by Raman, Photoluminescence and Fluorescence lifetime spectroscopy. Several aspects of CVD growth parameters have been investigated: growth zone geometry, precursors ratio, H2 utilization, and effect of different substrates. Moreover, structural integrity of the flakes grown in these experiments has been studied. It has been found that local changes of the S to Mo vapor ratio in the growth zone is a key factor for the change of shape, size and uniformity of the resulting MoS2 formations. Therefore, in order to obtain continuous monolayer films, the S to Mo vapor ratio is needed to be kept within a specific range throughout the substrate. Large area homogeneous growth of MoS2 film (3 cm x 4 cm) and flakes is achieved by using glass substrates with minimal stress contribution. Moreover, observations on the flakes revealed that growth zone geometry and hence residual stress accumulation has a profound effect on the fracture behavior of the flakes and their stability with time. Another 2D material family has been investigated using Density Functional Theory (DFT) calculations to find new electrene materials, which are 2D counterparts of electrides. Therefore, dynamically stable exfoliatable electrene family has been extended beyond Ca2N to Ba2As, Ba2P, Ba2Sb, Sr2P and Sr2N. Adsorption energies of Na, Ca, and K on these new electrenes have been found to be extremely low with very low diffusion energy barriers making these electrenes excellent candidates for ultrafast charging battery anode applications.