Controlled Growth of Large-scale Uniform 1T′ MoTe2 Crystals with Tunable Thickness and its photodetector application
The monoclinic phase 1T′ MoTe2 exhibits inversion symmetry as an anisotropic semi-metal, dictating its interesting quantum transport phenomenon and other novel physical properties. However, large-scale controlled growth of uniform MoTe2 crystal still remain great challenges, hindering its further fundamental research and applications for novel devices. Here, we report a modified growth method to synthesizing few-layer 1T′ MoTe2 crystals with large-scale uniformity by assistance of molecular sieves. The theoretical simulations demonstrated that due to the temperature-dependent formation energies of different edges, the edge of (010) orientation shown high thermodynamic stability than the (100) orientation, and results in the anisotropic growth behavior of 1T' MoTe2 while the temperature changes. The photoresponse of tri-layer 1T' MoTe2 based devices shown a wide spectrum reponse from 532 nm to 1550 nm. The photo-response time of 1T' MoTe2 crystal demonstrate that it supposes to be the synergistic mechanism of photo-conductive and photo-radiatation effect. Our findings not only provide a method for the controllable growth of anisotropic two-dimensional materials at wafer scale, but also explore a wide spectrum photodetector with the MoTe2-based device.