Spin-Enhanced Self-Powered Light Helicity Detecting Based on Vertical WSe2–CrI3 p–n Heterojunction

• Published in: ACS nano Vol. 18; no. 38; pp. 26261 - 26270
• Main Authors: Chen, Jiamin, Cheng, Zhixuan, Chen, Jiahao, Li, Minglai, Jia, Xionghui, Ran, Yuqia, Zhang, Yi, Li, Yanping, Yu, Tongjun, Dai, Lun
• Format: Journal Article
• Language: English
• Published: American Chemical Society 13.09.2024
• Subjects: self-powered light helicity detecting; magneto-optoelectronic response; two-dimensional magnetic semiconductor; vertical vdW heterostructure; TMDC
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.4c08185

Two-dimensional (2D) magnetic semiconductors offer an intriguing platform for investigating magneto-optoelectronic properties and hold immense potential in developing prospective devices when they are combined with valley electronic materials like 2D transition-metal dichalcogenides. Herein, we report various magneto-optoelectronic response features of the vertical hBN–FLG–CrI3–WSe2–FLG–hBN van der Waals heterostructure. Through a sensible layout and exquisite manipulation, an hBN–FLG–CrI3–FLG–hBN heterostructure was also fabricated on identical CrI3 and FLGs for better comparison. Our results show that the WSe2–CrI3 heterostructure, acting as a p–n heterojunction, has advantageous capability in light detection, especially in self-powered light helicity detecting. In the WSe2–CrI3 heterojunction, the absolute value of photocurrent I PH exhibits obvious asymmetry with respect to the bias V, with the I PH of reversely biased WSe2–CrI3 p–n heterojunction being larger. When the CrI3 is fully spin-polarized under a 3 T magnetic field, the reversely biased WSe2–CrI3 heterojunction exhibits advantageous capability in light helicity detecting. Both the short-circuit currents I SC and I PH show one-cycle fluctuation behaviors when the quarter-wave plate rotates 180°, and the corresponding photoresponsivity helicities can be as high as 18.0% and 20.1%, respectively. We attribute the spin-enhanced photovoltaic effect in the WSe2–CrI3 heterojunction and its contribution to circularly polarized light detection to the coordination function of the spin-filter CrI3, the valley electronic monolayer WSe2, and the spin-dependent charge transfer between them. Our work helps us understand the interplay between the magnetic and optoelectronic properties of WSe2–CrI3 heterojunctions and promotes the developing progress of prospective 2D spin optoelectronic devices.