Single‐Walled Carbon‐Nanotube‐Based Semitransparent Wide‐Bandgap Perovskite Solar Cell for Four‐Terminal Tandems

Photovoltaics play a crucial role in the global transition toward sustainable energy sources. As the demand for more efficient and cost‐effective solar technologies grows, innovative materials and designs are explored by researchers to enhance solar cell performance. Herein, the potential of single‐walled carbon nanotube (SWCNT) thin films as transparent electrodes in wide‐bandgap mixed halide perovskite solar cells is assessed. SWCNTs synthesized by the aerosol chemical deposition method are employed as the back electrode. The transparency of the perovskite cells makes them promising candidates for tandem top cells in a multi‐junction solar device. In these experiments, it is demonstrated that perovskite cells with SWCNT electrodes achieve a power conversion efficiency (PCE) of 12.63% in the reverse scan. When combined with a silicon bottom cell (PCE of 22.50%) in a tandem configuration, the overall efficiency reaches 24.37% despite a decrease in the bottom cell's performance due to shadowing effects. In these results, the potential of SWCNT electrodes in developing high‐efficiency tandem solar cells is highlighted. In this research, by combining the advantages of perovskite technology with the unique properties of SWCNTs, new avenues for advancing photovoltaic performance and contributing to the broader goal of sustainable energy production are opened.