Suppression of Magnetoresistance in Thin WTe2 Flakes by Surface Oxidation

摘要: Recent renewed interest in layered transition metal dichalcogenides stems from the exotic electronic phases predicted and observed single- few-layer limit. Realizing these requires preserving desired transport properties down to a monolayer, which is challenging. Surface oxides are known impart Fermi level pinning or degrade mobility on number of different systems, including black phosphorus. Semimetallic WTe2 exhibits large magnetoresistance due electron–hole compensation; thus, thin flakes could break balance suppress magnetoresistance. We show that develops an ∼2 nm thick amorphous surface oxide, shifts by ∼300 meV at surface. also observe dramatic suppression for flakes. However, semimetallic nature WTe2, effects well screened not domin...