Optically Enhanced Semitransparent Organic Solar Cells with Light Utilization Efficiency Surpassing 5.5%

Converting non-visual light into photocurrent while maintaining high visual transparency is vital for semitransparent organic solar cells (ST-OSCs) application, yet often challenging over insufficient invisible light-harvesting. Herein, spectrally selective optical manipulation for ST-OSCs with high visual light transparency and full-spectral non-visual light reflection is proposed by matching the optical admittance of ultrathin Ag films using ZnS and MgF2. The reflection of optically enhanced ST-OSCs at the spectral region beyond the human eye's response spectrum is improved and the transmission in the visual region is simultaneously enhanced. By further integrating an anti-reflective structure, the optimal structure boosts the average visible transmittance and power conversion efficiency of ST-OSCs to 44.3% and 12.6%, respectively, yielding a record light utilization efficiency of 5.6%. Corresponding flexible ST-OSCs with high mechanical stability implies that this work provides a facile and universal strategy for ST-OSCs aiming at building integrated photovoltaics.