High‐Efficiency Microcavity Semitransparent Organic Photovoltaics with Simultaneously Improved Average Visible Transmittance and Color Rendering Index

Semitransparent organic solar cells (ST‐OSCs) with vivid colors offer attractive prospects in aesthetical power‐generating windows. Unfortunately, they still suffer from certain limitations since the common approach for generating different colors is to adopt various photoactive layers, which complicates production processes and results in process‐induced performance deviations. Additionally, efficient ST‐OSCs with simultaneously improved average visible transmittance (AVT) and color rendering index (CRI) remain still challenging due to the trade‐off between photoelectric conversion efficiency (PCE) and AVT besides the interdependent/interactive relations of AVT and CRI. Herein, Ag/MoO 3 /Ag microcavity structure is introduced to delicately tune the absorption spectra of PM6:Y6 active material. The Ag/MoO 3 /Ag microcavity endows freely tunable colors to devices and meanwhile functions as a hole‐collecting layer. Under the guidance of optical simulation, the rationally designed ST‐OSCs with Ag/MoO 3 /Ag microcavity and Hf(ACB1) 4 electron collection layer display good eye comfort colors (purple, sky blue, cyan, green, and magenta) independently of the inherent color of PM6:Y6 active material, and show a close to 12% PCE with an AVT of 23.69% and a CRI of 92.5 for cyan devices. This work provides a practical way for achieving efficient ST‐OSCs with simultaneously improved AVT and CRI, and using them in building‐integrated photovoltaics as multicolored photovoltaic glass windows.