LAUSR

Wavelength-selective harvesting by organic solar cells (OSCs) has attracted significant research attention due to the unique potential of these materials for smart photovoltaic window applications. Here, a visibly transparent OSC is demonstrated by utilizing both near-infrared (NIR)-absorbing polymer donor and nonfullerene acceptor (NFA) materials with narrow optical bandgaps of less than 1.4 eV. Despite the substantial overlap in absorption spectra between the donor and acceptor, sufficient LUMO and HOMO energy offsets for efficient charge separation with concurrent very low voltage losses yield a high power conversion efficiency (PCE) of 9.1%. Moreover, by introducing an ultrathin Ag film (8 nm) as a transparent top electrode, semitransparent OSCs exhibit an excellent dual-side photovoltaic performance of 5.7% and 3.9% under bottom and top illumination, respectively, with a high transmittance of reaching 60% at wavelengths from 400-600 nm. This approach is expected to provide new insight into the development of highly efficient and transparent OSCs.