Flexible Color Tunability and High Transmittance Semitransparent Organic Solar Cells

Organic solar cells (OSCs) own unique advantages such as solution process, low cost, mechanical flexibility, and colorful semitransparency, making them preferable candidates to realize building‐integrated photovoltaics. To meet the requirements of architectural aesthetics, the Fabry–Perot micro‐cavity electrode is a good choice to achieve flexible color tunability. Herein, a Ag/MgF 2 /Ag micro‐cavity is constructed to act as a spectral selective transmission electrode. The micro‐cavity electrodes demonstrate high peak transmittance in specific wavelengths (blue, green, and red) by adjusting the thickness of dielectric layer MgF 2 , enabling the optimized colorful OSCs with blue, green, and red colors to exhibit high power conversion efficiencies of 13.15%, 13.03%, and 12.83% with peak transmittance of 35.5%, 33.7%, and 21.9%, respectively. Impressive results imply that our Ag/MgF 2 /Ag micro‐cavity electrodes possess great potential in practical colorful semitransparent OSCs applications.