Power Generation, Evaporation Mitigation, and Thermal Insulation of Semitransparent Polymer Solar Cells: A Potential for Floating Photovoltaic Applications

To explore the advantages of emerging semitransparent polymer solar cells (ST-PSCs), growing efforts have been devoted to developing multifunctional ST-PSCs for power-generation and heat-insulation applications. In this work, three groups of ST-PSCs are fabricated on the basis of fullerene and nonfullerene systems. We perform a systematic characterization of the power generation, transparency, and color perception of the ST-PSCs. The evaporation mitigation and heat-insulation properties of ST-PSCs are here evaluated for the first time. Gratifyingly, power conversion efficiencies of around 5.6–6.7% with average visible transmittances between 22 and 30% are obtained from the ST-PSCs under a large active area of 0.1 cm2. These ST-PSCs can serve as an efficient thermal barrier, which significantly lowers the surface temperature of water bodies, reduces the water evaporation rate, and suppresses the photothermal conversion efficiency of solar transpiration. This work discovers a new function for ST-PSCs and paves an intriguing prospect of floating the third-generation photovoltaic cells in the near future.