Abstract: Perovskite/Silicon tandem solar cells have attracted increasing attention in photovoltaic fields. However, expensive electrode materials and complex manufacturing procedures of top semitransparent perovskite solar cells (PSCs) and conventional bottom silicon (Si) solar cells are incompatible with economical production. Single-walled carbon nanotube (SWCNT) films have been regarded as promising transparent electrodes because of their hydrophobic nature, earth-abundant carbon sources, mechanical robustness, and good chemical stability. Herein, we report a new and simple four-terminal tandem device with the integration of SWCNT-based semitransparent PSCs and SWCNT-Si heterojunction solar cells. The employed SWCNT film is composed of high-crystallinity and small-bundled nanotubes with excellent optical transmittance and electric conductivity. It was adopted as the top electrode to realize semitransparent PSCs, which deliver a power conversion efficiency (PCE) of 12.02%, and the value can be further enhanced to 17.2% by introducing Spiro-OMeTAD into the SWCNT network. Interestingly, this semitransparent PSC has a bifacial feature and exhibits a bifaciality factor value of 91.1%. Moreover, the SWCNT film was transferred onto the surface of a Si wafer at room temperature to achieve the SWCNT-Si device with a PCE of 16.2%. Eventually, by integrating these two solar cells, a perovskite/SWCNT-Si tandem device with an efficiency of over 22% was obtained.

Key words: Single-walled carbon nanotubes, Transparent electrodes, Semitransparent perovskite solar cells, Four-terminal tandem devices