Effect evaluation of micro/nano structured materials on the performance of solar thermophotovoltaic system: An analysis based on measurement data

Selective absorber/emitter based on micro/nano materials can reshape the solar radiation spectrum and realize efficient energy conversion of solar thermo-photovoltaic (STPV) systems. In this study, based on the absorptance/emittance measurement results of typical micro/nano materials for selective emitters/absorbers, a STPV energy balance model is established to analyze the influence of selective materials on STPV performance. In particular, the system performance based on GaSb/InGaAsSb cascade cell is evaluated. The results show that for selective absorbers, its emittance has more impact on STPV performance than solar-spectrum absorptance whose effect is very limited when above 0.8. Since the emittance of selective absorber affects the system performance directly, an idea absorber should keep its emittance below 0.1. Moreover, two new concepts, effective-spectrum emittance and effective-energy emittance, are put forward innovatively to evaluate the performance of the emitter and simplify thermal-balance calculations. Among the two concepts, effective-energy emittance has a good correlation with the STPV performance. Based on parameter analysis, this study also obtains a STPV design scheme that uses broadband selective emitters to match multi-layer cascade cells. This study provides guidance for design and application of STPV systems.