Monolayer MoS_(2)of high mobility grown on SiO_(2)substrate by two-step chemical vapor deposition

We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo source.The electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport measurements.Furthermore,the direct van der Pauw transport also confirms its relatively high carrier mobility.Our study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement results.Such methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.