Herein, we achieved a controllable chemical vapor deposition (CVD) of few-layered uniform, highly crystalline metastable 1T′-MoTe₂ flakes by introducing iodine as a medium during the process. The growth mechanism is supported by X-ray diffraction (XRD), X-ray photoelectronic spectroscopy (XPS) and density function theory (DFT) calculations. During the growth process, the iodine atoms play a vital role in three key aspects: first, they lead to the change of the Mo–Te bond length; second, they induce the transformation of the volatile intermediate, which is essential for the controllable supply of Mo and Te and subsequent nucleation of highly crystalline 1T′-MoTe₂ flakes; third, they are easily removed due to their high volatility at elevated temperature, which could reduce the residue of impurities.

        https://doi.org/10.1021/acs.chemmater.6b05065