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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. [ABSTRACT FROM AUTHOR]

Heating is a knotty factor contributing to device degradation of flexible organic solar cells (FOSCs), and thermal regulation plays a crucial role in the realization of long operational lifetime. Herein, a passive cooling strategy for stable FOSCs is proposed by boosting the optical‐thermal radiative transfer to reduce the insufficient thermal dissipation and the elevated temperature caused by irradiation‐induced heating, while retaining their flexibility and portability. A spectrally selective coupling structure consisting of subwavelength hemisphere pattern and distributed Bragg reflector is integrated into FOSCs to collectively enhance out‐coupling of infrared radiation and limit near‐infrared absorption‐induced heat generation, leading to a reduced heat power intensity of 292.5 W cm−2 and the decreased working temperature by 9.6 °C under outdoor sunlight irradiation. The D18:Y6:PC71BM‐based FOSCs achieve a power conversion efficiency of over 17% with a prolonged T80 lifetime as long as one year under real outdoor working conditions. These results represent a new opportunity for enhancing the operational stability of FOSCs. [ABSTRACT FROM AUTHOR]

• Lateral charge collection range of silver nanowires are clarified via microscopic photocurrent images. • Doping LiTFSI in ZnO improves carrier mobility and energy level alignment with AgNWs. • Flexible organic solar cells achieve an efficiency of 18.0%. Although the transparency and sheet resistance of silver nanowire (AgNW) electrodes are comparable to those of rigid indium-tin-oxide electrodes, flexible organic solar cells (FOSCs) are still less efficient than their rigid counterparts. Herein, by recording the microscopic photocurrent images of AgNW-based FOSCs in operation, it has been revealed that the limited lateral charge collection range of AgNW leads to inevitable electrical energy loss. The regulation of carrier mobility and energy level of adjacent ZnO electron transport layer increases the effective collection range of AgNWs by 1.8 times and uniform the electrical potential distribution in FOSCs. The D18:Y6:PC 71 BM-based FOSCs achieve a power conversion efficiency of approaching 18%. Moreover, the performance drop of large-area FOSCs is significantly reduced due to the improved charge collection on large area scale. This work provides an intuitive insight into the electrical energy loss mechanism of AgNW electrodes and demonstrates an electric field regulation strategy in FOSCs. [ABSTRACT FROM AUTHOR]