Growth of 'W' doped molybdenum disulfide on graphene transferred molybdenum substrate
Journal article, 2018
In the present study, a novel method has been carried out to grow tungsten (W) doped molybdenum disulfide (MoS 2 ) on the graphene transferred TEM grid in a chemical vapor deposition (CVD) setup. Tungsten trioxide (WO 3 ) has been used as a source for 'W' while 'Mo' has been derived from Mo based substrate. Different experimental parameters were used in this experiment. Higher gas flow rate decreases the size of the sample flake and on other side increases the dopant concentrations. The interaction mechanism between Mo, S, W and oxygen (O) have been explored. The influence of oxygen seems to be not avoidable completely which also imposes effective growth condition for the reaction of Mo with incoming sulfur atoms. The difference in the migration energies of Mo, WO 3 , S clusters on the graphene and the higher reactivity of Mo clusters over other possibly formed atomic clusters on the graphene leads to the growth of W doped MoS 2 monolayers. Formation of MoS 2 monolayer and the nature of edge doping of 'W' is explained well with the crystal model using underlying nucleation principles. We believe our result provide a special route to prepare W doped MoS 2 on graphene substrate in the future.