High Mobility and Quantum Oscillations in Semiconducting BiOTe Nanosheets Grown by Chemical Vapor Deposition.

BiOTe has the smallest effective mass and preferable carrier mobility in the BiOX (X = S, Se, Te) family. However, compared to the widely explored BiOSe, the studies on BiOTe are very rare, probably attributed to the lack of efficient ways to achieve the growth of ultrathin films. Herein, ultrathin BiOTe crystals were successfully synthesized by a trace amount of O-assisted chemical vapor deposition (CVD) method, enabling the observation of ultrahigh low-temperature Hall mobility of >20 000 cm V s, pronounced Shubnikov-de Haas quantum oscillations, and small effective mass of ∼0.10 . Furthermore, few nm thick CVD-grown BiOTe crystals showed high room-temperature Hall mobility (up to 500 cm V s) both in nonencapsulated and top-gated device configurations and preserved the intrinsic semiconducting behavior with / ∼ 10 at 300 K and >10 at 80 K. Our work uncovers the veil of semiconducting BiOTe with high mobility and brings new blood into BiOX family.