Qiao Shuang, Liu Jihong, Yao Chengdong, Yang Ni, Zheng Fangyuan, Meng Wanqing, Wan Yi, Chow Philip C Y, Ki Dong-Keun, Zhang Lijie, Shi Yumeng, Li Lain-Jong
Hebei Key Laboratory of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, 071002, Baoding, China.
Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
Light Sci Appl. 2025 Jan 2;14(1):22. doi: 10.1038/s41377-024-01691-z.
Oxide materials with a non-centrosymmetric structure exhibit bulk photovoltaic effect (BPVE) but with a low cell efficiency. Over the past few years, relatively larger BPVE coefficients have been reported for two-dimensional (2D) layers and stacks with asymmety-induced spontaneous polarization. Here, we report a crucial breakthrough in boosting the BPVE in 3R-MoS by adopting edge contact (EC) geometry using bismuth semimetal electrode. In clear contrast to the typically used top contact (TC) geometry, the EC metal which strongly adheres to the edges and the subtrates can induce a pronounced tensile strain to the 3R-MoS, and the lateral contact geometry allows to completely access to in-plane polarization from underneath layers reachable by light, leading to >100 times of BPVE enhancement in photocurrent. We further design a 3R-MoS/WSe heterojunction to demonstrate constructive coupling of BPVE with the conventional photovoltaic effect, indicating their potential in photodetectors and photovoltaic devices.
具有非中心对称结构的氧化物材料表现出体光伏效应（BPVE），但电池效率较低。在过去几年中，对于具有不对称诱导自发极化的二维（2D）层和堆叠结构，已报道了相对较大的BPVE系数。在此，我们报告了一项关键突破，即通过使用铋半金属电极采用边缘接触（EC）几何结构来提高3R-MoS中的BPVE。与典型使用的顶部接触（TC）几何结构形成鲜明对比的是，牢固附着在边缘和基底上的EC金属会对3R-MoS施加明显的拉伸应变，并且这种横向接触几何结构能够完全从光可到达的下层获取面内极化，从而使光电流中的BPVE增强超过100倍。我们进一步设计了一种3R-MoS/WSe异质结，以证明BPVE与传统光伏效应的建设性耦合，这表明它们在光电探测器和光伏器件中的潜力。
