Liu Chang, Liang Tianyu, Sui Xin, Du Lena, Guo Quanlin, Xue Guodong, Huang Chen, You Yilong, Yao Guangjie, Zhao Mengze, Yin Jianbo, Sun Zhipei, Hong Hao, Wang Enge, Liu Kaihui
International Centre for Quantum Materials, Collaborative Innovation Centre of Quantum Matter, Peking University, Beijing, China.
State Key Lab for Mesoscopic Physics, Frontiers Science Centre for Nano-optoelectronics, School of Physics, Peking University, Beijing, China.
Nat Commun. 2025 Jan 9;16(1):544. doi: 10.1038/s41467-024-55623-x.
The anomalous photovoltaic effect (APE) in polar crystals is a promising avenue for overcoming the energy conversion efficiency limits of conventional photoelectric devices utilizing p-n junction architectures. To facilitate effective photocarrier separation and enhance the APE, polar materials need to be thinned down to maximize the depolarization field. Here, we demonstrate Janus MoSSe monolayers (0.67 nm thick) with strong spontaneous photocurrent generation. A photoresponsivity up to 3 mA/W, with ~ 1% external quantum efficiency and ultrafast photoresponse (50 ps) were observed in the MoSSe device. Moreover, unlike conventional 2D materials that require careful twist alignment, the photovoltage can be further scaled up by simply stacking the MoSSe layers without the need for specific control on interlayer twist angles. Our work paves the way for the development of high-performance, flexible, and compact photovoltaics and optoelectronics with atomically engineered Janus polar materials.
极性晶体中的反常光伏效应（APE）是克服利用p-n结结构的传统光电器件能量转换效率限制的一条有前途的途径。为了促进有效的光载流子分离并增强APE，需要将极性材料减薄以最大化去极化场。在此，我们展示了具有强自发光电流产生的Janus MoSSe单层（厚度约为0.67nm）。在MoSSe器件中观察到高达3mA/W的光响应度、约1%的外量子效率和超快光响应（约50ps）。此外，与需要仔细扭转对齐的传统二维材料不同，通过简单堆叠MoSSe层可以进一步提高光电压，而无需对层间扭转角进行特定控制。我们的工作为利用原子工程化的Janus极性材料开发高性能、柔性和紧凑型光伏及光电器件铺平了道路。
