Solution Processed Semi‐Transparent Organic Solar Cells Over 50% Visible Transmittance Enabled by Silver Nanowire Electrode with Sandwich Structure

Abstract Photovoltaic windows with easy installation for the power supply of household appliances have long been a desire of energy researchers. However, due to the lack of top electrodes that offer both high transparency and low sheet resistance, the development of high‐transparency photovoltaic windows for indoor lighting scenarios has lagged significantly behind photovoltaic windows where privacy issues are involved. Addressing this issue, this work develops a solution‐processable transparent top electrode using sandwich structure silver nanowires, realizing high transparency in semi‐transparent organic solar cells. The wettability and conducting properties of the electrode are improved by a modified hole‐transport layer named HP. The semi‐transparent solar cell exhibits good see‐through properties at a high average visible transmittance of 50.8%, with power conversion efficiency of 7.34%, and light utilization efficiency of 3.73%, which is the highest without optical modulations. Moreover, flexible devices based on the above‐mentioned architecture also show excellent mechanical tolerance compared with Ag electrode counterparts, which retains 94.5% of their original efficiency after 1500 bending cycles. This work provides a valuable approach for fabricating solution‐processed high transparency organic solar cells, which is essential in future applications in building integrated photovoltaics.