Controllable 2H-to-1T' phase transition in few-layer MoTe2
Controllable 2H-to-1T' phase transition in few-layer MoTe2
复制标题
几层 MoTe2 中可控的 2H 到 1T™ 相变
DOI：
10.1039/c8nr06115g
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发表时间：
2018-11-14
期刊：
影响因子：
6.7
通讯作者：
Zhang, Xue-Ao
中科院分区：
文献类型：
--
作者：
Tan, Yuan;Luo, Fang;Zhang, Xue-Ao
大多数二维(2D)过渡金属二卤化物(TMD)表现出不止一个结构相，这导致了石墨烯以外的许多引人注目的物理和潜在的器件应用。在这里，我们证明了一条可行的路线，触发2H到1T‘相变在少层二碲化钼(MoTe2)。系统地研究了激光功率和辐照时间对相变的影响，揭示了累积加热效应是这种相变的主要驱动力。通过适当调整激光功率和照射时间，我们可以控制MoTe2的结构相为2H、2H+1T‘和1T’。激光辐照的MoTe2在较低温度下热处理后，2H组分被完全抑制，1T相更加稳定，说明2H-1T‘相变不可逆的微观原因是激光局部瞬时加热在MoTe2中形成了Te空位。我们的发现与MoTe2的独特性质一起，为基于2D TMD及其异质结构的高性能纳米电子学和光电子学铺平了道路。
Most two-dimensional (2D) transition metal dichalcogenides (TMDs) exhibit more than one structural phase, leading to a number of remarkable physics and potential device applications beyond graphene. Here, we demonstrated a feasible route to trigger 2H-to-1T' phase transition in few-layer molybdenum ditelluride (MoTe2) by laser irradiation. The effects of laser power and irradiation duration were systematically studied in this study, revealing the accumulated heating effect as the main driving force for such a phase transition. By carefully adjusting laser power and irradiation time, we could control the structural phases of MoTe2 as 2H, 2H + 1T', and 1T'. After thermal annealing at a rather low temperature, the laser-irradiated MoTe2 showed a completely suppressed 2H component and a more stabilized 1T phase, demonstrating that the microscopic origin of the irreversible 2H-to-1T' phase transition is the formation of Te vacancies in MoTe2 due to laser local instantaneous heating. Our findings together with the unique properties of MoTe2 pave the way for high-performance nanoelectronics and optoelectronics based on 2D TMDs and their heterostructures.