Two-Dimensional Semiconductors Grown by Chemical Vapor Transport.

Developing controlled approaches for synthesizing high-quality two-dimensional (2D) semiconductors is essential for their practical applications in novel electronics. The application of chemical vapor transport (CVT), an old single-crystal growth technique, has been extended from growing 3D crystals to synthesizing 2D atomic layers by tuning the growth kinetics. Both single crystalline individual flakes and continuous films of 1 L MoS2 were successfully obtained with CVT approach at low growth temperatures of 300-600 °C. The obtained 1 L MoS2 exhibits high crystallinity and comparable mobility to mechanically exfoliated samples, as confirmed by both atomic resolution microscopic imaging and electrical transport measurements. Besides MoS2 , this method was also used in the growth of 2D WS2 , MoSe2 , Mox W1-x S2 alloys, and ReS2 , thus opening up a new way for the controlled synthesis of various 2D semiconductors.