Methods of synthesis and fabrication of a transition metal dichalcogenide (TMD) structures are disclosed. A method can include first patterning a transition metal (TM) on a substrate and placing the substrate in a process chamber. Oxygen can be applied to the transition metal on the substrate and a mixture of highly reactive transition metal oxides can be formed and simultaneously thinned down by sublimation. Finally, a chalcogen can be applied to the substrate and a transition metal dichalcogenide structure can be formed.