摘要： This work performs a detailed theoretical analysis for low-concentration solar thermophotovoltaic (STPV) system with both solar absorber and thermal emitter made of previously-developed selective meta?lms along with a cavity re?ector for performance enhancement. When paired with an InGaAsSb cell, the initial meta?lm structure shows an STPV system e?ciency of 7.1% at 50 suns, where about half of the incident solar energy is lost through the thermal emission from the top surface of the absorber according to energy loss analysis. In order to enhance the STPV system performance, the meta?lm layer thicknesses of the solar absorber and those of the thermal emitter are optimized at 50 suns, increasing the STPV system e?ciency from 7.1% to 10.2%. Moreover, a cavity re?ector above the absorber is considered to recycle the infrared photons emitted from the top surface of the absorber. The e?ects of the size and the re?ectivity of the cavity re?ector on the e?ciency are discussed. The results show that, the e?ciency of the optimized meta?lm based STPV system at 50 suns can be increased from 10.2% to 17.4% with a cavity made of ideal re?ectors.