Authors: Dongyan Liu, Jinhua Hong, Xiaobo Li, Xing Zhou, Bao Jin, Qiannan Cui, Jinping Chen, Qingliang Feng, Chunxiang Xu, Tianyou Zhai, Kazu Suenaga, Hua Xu
Published: 2020-02-26
Source: Full article
Abstract2D transition metal chalcogenides (TMDs) with different compositions, phase structures, and properties offer giant opportunities for building novel 2D lateral heterostructures. However, the studies to date have been largely limited to homophase TMD heterostructures, while the construction of heterophase TMD heterostructures remains a challenge. Herein, the synthesis of 2H‐1T′ WS2‐ReS2 heterophase junctions with high‐quality interface structure via a hydrogen‐triggered one‐pot growth approach is reported. Sequential introduction of hydrogen during growth system, which acts as a “switch” to selectively turn off the growth of ReS2 while turning on the growth of WS2, allows WS2 to seamlessly grow around ReS2 to form the WS2‐ReS2 heterojunction. Moreover, WS2 prefers to nucleate at the vertices of ReS2 grain with fixed lattice orientation, which makes the surrounding WS2 grains merge into single crystal. Scanning transmission electron microscopy reveals high crystal quality of the heterojunction with an atomically sharp 2H‐1T′ heterophase interface. Transient absorption spectroscopy indicates that the photocarriers can effectively separate at the heterophase interface. Based on the high quality heterophase junction, prominent rectification characteristics and polarization‐dependent photodiode properties are achieved. This study provides a robust way for the controlled synthesis of 2D heterophase structures, which is essential for their fundamental studies and device applications.