Plasmonic light trapping for enhanced light absorption in film-coupled ultrathin metamaterial thermophotovoltaic cells  

作　　者：Qing NI Hassan ALSHEHRI Yue YANG Hong YE Liping WANG 

机构地区：[1]School for Engineering of Matter, Transport & Energy, Arizona StateUniversity, Tempe, AZ 85287, USA [2]Department of Thermal Scienceand Energy Engineering, University of Science and Technology ofChina, Hefei 230027, China [3]School of Mechanical Engineering and Automation, Harbin Institute of Technology (Shenzhen), Shenzhen518052, China [4]Department of Thermal Science and Energy Engineering, University ofScience and Technology of China, Hefei 230027, China

出　　处：《Frontiers in Energy》2018年第1期185-194,共10页能源前沿（英文版）

摘　　要：Ultrathin cells have gained increasing attention due to their potential for reduced weight, reduced cost and increased flexibility. However, the light absorption in ultrathin cells is usually very weak compared to the corresponding bulk cells. To achieve enhanced photon absorption in ultrathin thermophotovoltaic （TPV） cells, this work proposed a film-coupled metamaterial structure made of nanometer-thick gallium antimonide （GaSh） layer sandwiched by a top one-dimensional （1D） metallic grating and a bottom metal film. The spectral normal absorptance of the proposed structure was calculated using the rigorous coupled-wave algorithm （RCWA） and the absorption enhancement was elucidated to be attributed to the excitations of magnetic polariton （MP）, surface plasmon polariton （SPP）, and Fabry-Perot （FP） resonance. The mechanisms of MP, SPP, and FP were further confirmed by an inductor-capacitor circuit model, disper- sion relation, and phase shift, respectively. Effects of grating period, width, spacer thickness, as well as incidence angle were discussed. Moreover, short-circuit current density, open-circuit voltage, output electric power,and conversion efficiency were evaluated for the ultrathin GaSb TPV cell with a film-coupled metamaterial structure. This work will facilitate the development of next- generation low-cost ultrathin infrared TPV cells.Ultrathin cells have gained increasing attention due to their potential for reduced weight, reduced cost and increased flexibility. However, the light absorption in ultrathin cells is usually very weak compared to the corresponding bulk cells. To achieve enhanced photon absorption in ultrathin thermophotovoltaic （TPV） cells, this work proposed a film-coupled metamaterial structure made of nanometer-thick gallium antimonide （GaSh） layer sandwiched by a top one-dimensional （1D） metallic grating and a bottom metal film. The spectral normal absorptance of the proposed structure was calculated using the rigorous coupled-wave algorithm （RCWA） and the absorption enhancement was elucidated to be attributed to the excitations of magnetic polariton （MP）, surface plasmon polariton （SPP）, and Fabry-Perot （FP） resonance. The mechanisms of MP, SPP, and FP were further confirmed by an inductor-capacitor circuit model, disper- sion relation, and phase shift, respectively. Effects of grating period, width, spacer thickness, as well as incidence angle were discussed. Moreover, short-circuit current density, open-circuit voltage, output electric power,and conversion efficiency were evaluated for the ultrathin GaSb TPV cell with a film-coupled metamaterial structure. This work will facilitate the development of next- generation low-cost ultrathin infrared TPV cells.

关 键 词：METAMATERIAL THERMOPHOTOVOLTAIC plasmo-nics light trapping selective absorption 

分 类 号：TN912.15[电子电信—通信与信息系统] O431.2[电子电信—信息与通信工程]