A polarization-insensitive fishnet/spacer/mirror plasmonic absorber for hot electron photodetection application  

作　　者：Zhiqiang Yang Kang Du Wending Zhang Soojin Chua Ting Mei 杨志强;杜康;张文定;蔡树仁;梅霆(Key Laboratory of Space Applied Physics and Chemistry,Ministry of Education,and Shaanxi Key Labora tory of Optical Information Technology,School of Science,North Western Polytechnical University,Xi'an 710072,China;Department of Electrical and Computer Engineering,National University of Singapore,Singapore 117583,Singapore;LEES Program,Singapore-MIT Alliance for Research&Technology(SMART),Singapore 138602,Singapore)

机构地区：[1]Key Laboratory of Space Applied Physics and Chemistry,Ministry of Education,and Shaanxi Key Labora tory of Optical Information Technology,School of Science,North Western Polytechnical University,Xi'an 710072,China [2]Department of Electrical and Computer Engineering,National University of Singapore,Singapore 117583,Singapore [3]LEES Program,Singapore-MIT Alliance for Research&Technology(SMART),Singapore 138602,Singapore

出　　处：《Chinese Optics Letters》2020年第5期63-67,共5页中国光学快报（英文版）

基　　金：the National Natural Science Foundation of China (NSFC)(Nos. 91950207,61675171,and 61675169);Fundamental Research Funds for the Central Universities of China (Nos. 3102017-HQZZ022 and 3102017zy021)。

摘　　要：A polarization-insensitive plasmonic absorber is designed consisting of Au fishnet structures on a TiO2 spacer/Ag mirror. The fishnet structures excite localized surface plasmon and generate hot electrons from the absorbed photons, while the TiO2 layer induces Fabry–Perot resonance, and the Ag mirror acts as a back reflector.Through optimizing the TiO2 layer thickness, numerical simulation shows that 97% of the incident light is absorbed in the Au layer. The maximum responsivity and external quantum efficiency of the device can approach 5 mA/W and ~1%, respectively, at the wavelength of 700 nm.

关 键 词：plasmonic absorber Fabry–Perot resonance internal photoemission surface plasmon 

分 类 号：TN311.7[电子电信—物理电子学] O53[理学—等离子体物理]