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.