二维材料是构筑下一代光/电子器件的理想载体，其性能主要取决于材料晶相。实现材料晶相的可调控是二维材料未来得到广泛应用的关键。然而，通常二维材料不同相之间能量差异较大，需要通过极端条件才能实现转变，因而难以得到广泛研究和应用。MoTe2由于其H（半导体性）和T’（半金属性）相之间能量差异极小（~ 0.03 eV），因而可以通过并不严苛的外界能量刺激实现相转变。本项目拟通过气相沉积方法制备不同晶相MoTe2单晶，结合PZT铁电衬底，实现电场调控下MoTe2可逆相转变。铁电衬底可以通过电场进行极化，在零能耗条件下，其剩余极化强度能够满足MoTe2相转变的电荷注入浓度要求。同时，关注相转变诱发及其演化的具体过程，主要考察不同晶相，不同层数，不同堆垛模式的二维MoTe2中相转变的演化规律。本项目的研究工作将有助于理解电场调控下二维材料相转变内在机制，加速二维材料在下一代光/电子器件的应用进程。

Two-dimensional (2D) materials are the ideal blocks for next generation optical/electronic devices, and the properties of which are largely dependent on the phase type. Thus the key for widely utilization of 2D materials in future is to control the phase. However, the energy difference between various phases of 2D materials is generally so large that the phase transition merely takes place under extreme conditions, hindering its further researches and applications. MoTe2 has considerable small energy difference (~ 0.03 eV) between its H (semiconducting) and T’ (semimetallic) phases, thus the phase transition could be triggered under mild conditions. This project is aiming to realize controllable phase transition in chemical vapor deposition grown MoTe2 single crystals via PZT ferroelectric substrate modulated by external electronic field. Ferroelectric substrate can be polarized under electric field and its remanent polarization under zero input fully meets the charge density injection requirement for the phase transition of MoTe2. Meantime, we will focus on the detailed process of phase transition and mainly on the phase transition process in samples with various phase types, layer numbers and stacking modes. This project would shed light on the mechanism of phase transition in 2D materials under electric field, and speed up the utilization process of 2D materials in next generation of optical/electronic devices.