High‐Performance Colorful Organic Photovoltaics with Microcavity Resonance Color Filter

Abstract Microcavity resonance is an effective technique for making promising semitransparent organic photovoltaics (ST‐OPVs) even more aesthetically attractive with high color saturation, by tailoring the visible transmittance spectrum to narrow the transmission peak. In this study, a distinctive microcavity resonance color filter (CF) structure of silver/ bismuth(III) fluoride /silver (Ag/BiF 3 /Ag) is integrated upon the rear transparent electrode, which simultaneously achieves high color purity and high power conversion efficiency (PCE) for colorful OPVs. By precisely regulating the thickness of the BiF 3 layer, colorful OPVs with a wide color gamut and high color purity are achieved, including the colors of indigo, blue, bluish‐green, green, orange, and red, as well as compound color devices with dual or multiple transmission peaks in the visible region. A recorded PCE of 16.27% is obtained for the indigo OPV, with the Commission Internationale de l´Eclairage 1931 coordinates of (0.164 and 0.087) and a maximum transmittance of 18.7% at the transmission peak wavelength of 393 nm. Furthermore, colorful OPVs as color reflectors are systematically investigated under different light incident surfaces. The improved stability of colorful OPVs is attributed to the excellent moisture resistance of BiF 3 . The colorful OPVs with desired transmitted/reflected colors, and wide color gamut show great potential for future energy harvesting solutions.