All-Semiconductor Plasmonic Resonator for Surface-Enhanced Infrared Absorption Spectroscopy
Wei Wei,
Jinpeng Nong,
Xiao Jiang,
Na Chen,
Suqin Luo,
Linlong Tang
Affiliations
Wei Wei
Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
Jinpeng Nong
Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
Xiao Jiang
Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
Na Chen
Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
Suqin Luo
Chongqing Research Center for Advanced Materials, Chongqing Academy of Science and Technology, Chongqing 401123, China
Linlong Tang
Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China
Infrared absorption spectroscopy remains a challenge due to the weak light-matter interaction between micron-wavelengthed infrared light and nano-sized molecules. A highly doped semiconductor supports intrinsic plasmon modes at infrared frequencies, and is compatible with the current epitaxial growth processing, which makes it promising for various applications. Here, we propose an all-semiconductor plasmonic resonator to enhance the infrared absorption of the adsorbed molecules. An optical model is employed to investigate the effect of structural parameters on the spectral features of the resonator and the enhanced infrared absorption characteristics are further discussed. When a molecular layer is deposited upon the resonator, the weak molecular absorption signal can be significantly enhanced. A high enhancement factor of 470 can be achieved once the resonance wavelength of the resonator is overlapped with the desired vibrational mode of the molecules. Our study offers a promising approach to engineering semiconductor optics devices for mid-infrared sensing applications.
