Spectral Splitting as a Route to Promote Total Efficiency of Hybrid Photovoltaic Thermal with a Halide Perovskite Cell

Integrating photovoltaic (PV) perovskite solar cells and photothermal (PT) collectors into a hybrid photovoltaic thermal (PVT) is a promising method to further improve the conversion efficiency of solar energy via salvaging the near-infrared energy. Herein, a 1D photonic crystal of Si/GeO2 to construct a spectrally selective PV-PT splitter that selectively reflects solar energy in the PV band while absorbing the rest is utilized. The fabricated PV-PT splitter reveals a considerable reflectance of 92.3% in the PV band, a comprehensive absorptance of 52.1% in the PT band, as well as good angular independence over a wide incident range of 0-70 degrees. The hybrid PVT design with the Si/GeO2 spectral splitter/absorber and a perovskite solar cell (PSC) acquires a solar-to-electrical efficiency of 29.3% higher than the single PSC (24.6%). In addition, the temperature of PSCs in the hybrid PVT design under 1 kW m(-2) solar irradiation can be significantly reduced by 15 degrees C owing to suppression of ineffectively converted incident photons on the PV cells. This appealing strategy highlights a new avenue for further enhancing the total electrical efficiency via broadening the utilization of the entire solar spectrum in the hybrid PVT design integrated with wide-bandgap perovskite solar cells.

Automated summary

Integrating PV perovskite solar cells and PT collectors into a hybrid PVT system can improve conversion efficiency by salvaging near-infrared energy. A 1D photonic crystal of Si/GeO2 is used to construct a spectrally selective PV-PT splitter that selectively reflects solar energy in the PV band while absorbing the rest. The hybrid PVT design with the Si/GeO2 spectral splitter/absorber and a perovskite solar cell achieves a higher solar-to-electrical efficiency of 29.3% compared to a single PSC of 24.6%.