Room-temperature growth of colloidal Bi2Te3 nanosheets

In this work, we report the colloidal synthesis of Bi2Te3 nanosheets with controlled thickness, morphology and crystallinity at temperatures as low as 20 degrees C. Grown at room temperature, Bi2Te3 exhibits two-dimensional morphology with thickness of 4 nm and lateral size of 200 nm. Upon increasing the temperature to 170 degrees C, the nanosheets demonstrate increased thickness of 16 nm and lateral dimensions of 600 nm where polycrystalline nanosheets (20 degrees C) are replaced by single crystal platelets (170 degrees C). Rapid synthesis of the material at moderately low temperatures with controllable morphology, crystallinity and consequently electrical and thermal properties can pave the way toward its large-scale production for practical applications.