Efficient Semitransparent Organic Solar Cells with Highly Transparent Metal Front Electrodes

Semitransparent organic solar cells (STOSCs) exhibit great potential for electricity-generating windows, self-powered greenhouses, and vehicle-integrated and building-integrated photovoltaics, with their tunable absorption spectrum and rapidly improved power conversion efficiencies (PCEs). PCE and average visible transmittance (AVT) are two key parameters to be moderated for STOSCs. In this work, we report efficient STOSCs that can maintain over 85% efficiency of the opaque OSCs at an AVT of over 22.5%, enabled by highly transparent gold grid front electrodes with an average transmittance of over 95%. The gold grids prepared by mask-less direct-write lithography technology show great tunability in morphology, transmittance, and resistance, based on which the as-fabricated STOSCs achieves an PCE of 10.14%, corresponding to an opaque device efficiency of 11.93%. Considering the roaring efficiency of nonfullerene based OSCs of over 19%, the PCE of STOSCs is promised to exceed 16% at AVTs above 20% with such a general electrode engineering strategy.