低对称性的亚波长阵列增强型的GeSe偏振探测器  

Low symmetric sub-wavelength array enhanced lensless polarization-sensitivity photodetector of germanium selenium

作　　者：周子琦 沈涛 王盼 郭泉林 王卿赫 马辰俊 辛凯耀 赵凯 于雅俐 秦彪 刘岳阳 杨珏晗 洪浩 刘开辉 刘灿 邓惠雄 魏钟鸣 Ziqi Zhou;Tao Shen;Pan Wang;Quanlin Guo;Qinghe Wang;Chenjun Ma;Kaiyao Xin;Kai Zhao;Yali Yu;Biao Qin;Yue-Yang Liu;Juehan Yang;Hao Hong;Kaihui Liu;Can Liu;Hui-Xiong Deng;Zhongming Wei(State Key Laboratory of Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;State Key Laboratory for Mesoscopic Physics,Frontiers Science Centre for Nano-optoelectronics,School of Physics,Peking University,Beijing 100871,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Department of Physics,Renmin University of China,Beijing 100872,China)

机构地区：[1]State Key Laboratory of Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China [2]State Key Laboratory for Mesoscopic Physics,Frontiers Science Centre for Nano-optoelectronics,School of Physics,Peking University,Beijing 100871,China [3]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [4]Department of Physics,Renmin University of China,Beijing 100872,China

出　　处：《Science Bulletin》2023年第2期173-179,M0004,共8页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(62125404,62004193,61922077,12274456,92163206,51991342,and 11874347);the Strategic Priority Research Program of Chinese Academy of Sciences(XDB43000000);the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030002);the National Key R&D Program of China(2021YFA1400502 and 2022YFA1405600);supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences(Y2021042);the Nanofabrication Laboratory in the National Centre for Nanoscience and Technology for the electron beam lithography。

摘　　要：偏振敏感光电探测器可通过探测光偏振态的变化从而分辨纹理、应力和粗糙度等多种信息,在安全、医疗诊断和航空航天领域具有独特的优势.基于面内各向异性的二维材料的偏振光探测器可简化传统探测器的复杂透镜系统,促进了光电器件的集成化与小型化.然而,基于面内各向异性的二维材料的偏振光探测器的光电流各向异性比不足(通常小于10),限制了偏振信号的检测分辨率.本文设计了基于二维硒化亚锗(GeSe)的亚波长阵列(SWA)结构,进一步提高其各向异性灵敏度,并将光电流各向异性从1.6提高到18.本研究发现,SWA结构可以进一步增强电荷分布的不对称性,提高GeSe材料在扶手椅方向上的光吸收和光电跃迁概率,从而提高了偏振灵敏度.此外,基于GeSe SWA的光电探测器在808 nm的近红外波长下表现出宽的功率范围(40 dB)和弱光探测能力(0.1 LUX).该工作为提高二维材料的偏振灵敏度提供了可行性指导,将有利于促进高分辨率偏振成像传感器的发展.Polarization-sensitive photodetectors, with the ability of identifying the texture-, stress-, and roughnessinduced light polarization state variation, displace unique advantages in the fields of national security,medical diagnosis, and aerospace. The utilization of in-plane anisotropic two-dimensional(2D) materials has led the polarization photodetector into a polarizer-free regime, and facilitated the miniaturization of optoelectronic device integration. However, the insufficient polarization ratio(usually less than 10)restricts the detection resolution of polarized signals. Here, we designed a sub-wavelength array(SWA) structure of 2D germanium selenium(Ge Se) to further improve its anisotropic sensitivity, which boosts the polarized photocurrent ratio from 1.6 to 18. This enhancement comes from the combination of nano-scale arrays with atomic-scale lattice arrangement at the low-symmetric direction, while the polarization-sensitive photoresponse along the high-symmetric direction is strongly suppressed due to the SWA-caused depolarization effect. Our mechanism study revealed that the SWA can improve the asymmetry of charge distribution, attenuate the matrix element in zigzag direction, and the localized surface plasma, which elevates the photo absorption and photoelectric transition probability along the armchair direction, therefore accounts for the enhanced polarization sensitivity. In addition, the photodetector based on Ge Se SWA exhibited a broad power range of 40 d B at a near-infrared wavelength of 808 nm and the ability of weak-light detection under 0.1 LUX of white light(two orders of magnitude smaller than pristine 2D Ge Se). This work provides a feasible guideline to improve the polarization sensitivity of 2D materials, and will greatly benefit the development of polarized imaging sensors.

关 键 词：光电探测器 偏振灵敏度 光电器件 弱光探测 二维材料 透镜系统 医疗诊断 电荷分布 

分 类 号：TN15[电子电信—物理电子学]