Ultrahigh yield and large-scale fast growth of large-size high-quality van der Waals transition-metal telluride single crystals

Stable, rapid, and large-scale production of high-quality, large-size two-dimensional (2D) van der Waals single crystals is an important prerequisite for realizing the potential of highly integrated 2D devices. Here, we report a chloride-mediated chemical vapor transport (CVT) approach to achieve large-scale production of MoTe2 and WTe2 single crystals with lateral sizes up to 2 cm and extremely high quality. The largest magnetoresistance and carrier mobility can reach 170% and 1,390.09 cm(2) V-1 s(-1) for 2H-MoTe2 crystals and 506,017% and 11,952.10 cm(2) V-1 s(-1) for Td-WTe2 crystals, respectively, and all are among the best reported ones. Compared with the conventional CVT method, which has a long growth cycle and much reactive reagent surplus, the growth speed of the current method is about 73 to 9,144 times faster, with ultrahigh yields of nearly 100%. The high crystallinity guarantees the crystals can be easily exfoliated to large-scale 2D crystals down to monolayers for assembling 2D high-performance devices.

Automated summary

This study reports a chloride-mediated CVT method for large-scale production of MoTe2 and WTe2 single crystals with extremely high quality and the highest levels of magnetoresistance and carrier mobility. The method offers significantly faster growth speed and nearly 100% yield compared to conventional methods, and the high crystallinity allows easy exfoliation to obtain large-scale 2D crystals for assembling high-performance devices.