Modeling and property study of thermoelectric converter based on subwavelength photothermal absorption structure

Abstract

Achieving light absorption and conversion in a wide wavelength region and large angles of incidence is an effective way to improve the efficiency of thermoelectric devices. In this work, the thermoelectric converter device with a sub-wavelength photothermal absorption structure is designed, and the thermoelectric device is adapted to medium and high-temperature working environments by introducing PbS and SiGe thermoelectric materials. By changing the material of the surface heat-absorbing layer and studying the adjustment effect of the shape and size of the sub-wavelength photothermal absorption structure on reflectivity, the perfect absorption of sunlight with a wide wavelength region and large angles of incidence is realized, and the maximum photothermal conversion is achieved. Furthermore, the qualitative and quantitative relationships between the thermal absorption and thermoelectric conversion performance of PbS and SiGe thermoelectric materials and the physical parameters of surface subwavelength photothermal absorption structures are studied, so as to maximize the absorption and conversion of thermal energy into electrical energy. This work provides research ideas for the design of perfect thermoelectric devices.