Efficient Semi‐Transparent Organic Solar Cells with High Color Rendering Index Enabled by Self‐Assembled and Knitted AgNPs/MWCNTs Transparent Top Electrode via Solution Process

Semi‐transparent organic solar cells (STOSCs) have attracted tremendous attention in power‐generating windows for buildings and automobiles. Although STOSCs based on vacuum‐deposited thin metal films exhibited power conversion efficiency exceeding 10%, solution‐processed top transparent electrode (TE) is desirable for large‐area and low‐cost fabrication of STOSCs. Here, we present a self‐assembled and knitted Ag nanoparticles/multi‐walled carbon nanotubes composite thin film by solution process as transparent top electrode for STOSC. The composite film exhibits an extremely low sheet resistance of 14.5Ω sq −1 , an average visible transmittance (AVT) of ≈67%, and a high color rendering index (CRI) of 97. The optimized device with solution‐processed top TE achieves an AVT of 36% and a high CRI of 90. This work paves a simple and promising route towards low‐cost fabrication of power‐generating window.