Liujiang Zhou1 Amanda J. Neukirch1 Zhiwen Zhuo2 Sergei Tretiak1

1, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
2, University of Science and Technology of China, Hefei, , China

Two-dimensional (2D) layered materials with weak interlayer coupling and sufficiently large electronic band gap as well as high carrier mobility are highly desired for future high-speed electronic devices due to their super high feasibility in experimental accessibility and functionality. Here we present a systematic study of 2D double-metal-layered scandium chloride carbides (Sc2CCl2), which displays extremely high carrier mobility and rather weak interlayer coupling, which endows Sc2CCl2 intrinsic layer-decoupled electronic, vibrational and optical properties in few-layer structures. Sc2CCl2 also possesses rather high and highly anisotropic carrier mobility of up to 72 × 103 and 15 × 103 cm2 V-1 s-1 for electrons and holes, respectively, far higher than those of conventional 2D materials, such as molybdenum disulfide (60–200 cm2 V-1 s-1) and few-layer black phosphorus (~103 cm2 V-1 s-1). The observed electronic and optical features suggest few-layer Sc2CCl2 are also promising donor materials for light harvesting in solar cell and photocatalysts for water splitting. These results enable probing of 2D-like systems without the requirements for the fine preparation of monolayers, and greatly enrich the family 2D transition-metal-based materials and hint for a new platform for the next-generation high-speed electronics.