Colorful polymer solar cells employing an energy transfer dye molecule

Over the past decade, there has been significant improvement in the performance of polymer solar cells (PSCs). Devices with power conversion efficiency (PCE) well over 10% have been developed and in some cases the estimated device lifetime is approaching 10 years. In contrast, there has been limited research into the aesthetics of PSCs, which may be crucial to successful commercialization. Here, we report a variety of colored polymer solar cells by employing different amounts of an energy transfer dye molecule in a polymer-polymer binary photoactive system. In fact, by varying the amount of the dye molecule in the device, PSCs covering one third of the Munsell standard color chart (in this case green to red) are observed. Additionally, the dye molecule serves as an energy transfer donor to the host photoactive system which leads to 10% enhancement in PCE. Our approach may broaden the appeal of PSCs in applications where aesthetics are important. We report polymer solar cells with different colors by employing an energy transfer dye molecule in a polymer-polymer binary photoactive system. The guest dye molecule allows tuning of the solar cell color and is an energy transfer donor to the host photoactive system. This design allows broad tuning of the solar cell color from blue green to purple red, covering one third of the Munsell standard chart, without lowering the power conversion efficiency. [Display omitted] •A guest dye molecule employed in photoactive layers tunes the color of solar cells.•The guest dye also functions as an energy transfer donor to host photoactive system.•Energy transfer dye extends color variety of solar cells without efficiency loss.