Near-Infrared Polarization-Sensitive Detection by All-Si Plasmonic Hot Electron Detectors

• Published in: Nano letters
• Main Authors: Tian, Shuoqiu, Yuan, Wentao, Yu, Yu, Guo, Jinyu, Liu, Kangping, Tong, Xujie, Chen, Qiucheng, Wu, Qingxin, Quan, Hao, Zhou, Jing, Chen, Yifang
• Format: Journal Article
• Language: English
• Published: United States 09.10.2024
• Subjects: Au antenna/Si nanowire metasurface; plasmonic hot electron photodetector; polarization photocurrent ratio; polarization-sensitive detection; short infrared wavelength
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/acs.nanolett.4c03959

Polarization-sensitive optoelectronic detection has been achieved by an all-Si detector in the NIR range, based on plasmon hot electron generation/internal photoemission effect. An advanced architecture with a specially designed anisotropic metasurface was developed and structurally optimized for maximizing the internal quantum efficiency (IQE). Assisted by finite difference time domain (FDTD) simulations, the well-designed device exhibits a maximum optical absorption of 80% around 1.45 μm, corresponding to an optical discrimination ratio of 120. Optoelectronic measurements show the peak responsivity and detectivity of 51.2 mA/W and 8.05 × 10 cm Hz /W, respectively, at 1.45 μm. A high polarization photocurrent ratio of 35 nm is also achieved at 1.55 μm. Moreover, the optoelectronic response can be tuned by a back-gate bias. Last but not least, we built up a model for theoretically estimating the IQE, which provides instructive guidance for further enhancing the optoelectronic performance of hot electron detectors.