4-T CdTe/Perovskite Thin Film Tandem Solar Cells with Efficiency >24%

An integration of perovskite and cadmium telluride (CdTe) solar cells in a tandem configuration has the potential to yield efficient thin-film tandem solar cells. Owing to the promise of higher efficiency at low cost, the presented study aims to explore the potential for combining this commercially established CdTe photovoltaics (PV) with next-generation perovskite PV. Here, we developed four-terminal (4-T) CdTe/perovskite tandem solar cells, starting with 18.3% efficient near-infrared-transparent perovskite solar cells (NIR-TPSCs) with an average transmission (Tavg) of 24.76% in the 300–900 nm wavelength range. These were then integrated with 19.56% efficient opaque CdTe solar cells, achieving 23.42% efficiency in a 4-T tandem configuration. Additionally, using a refractive index matching liquid increases the overall power conversion efficiency (PCE) to 24.2%. This pioneering achievement marks the first instance of a 4-T CdTe/perovskite thin-film tandem solar cell exceeding a PCE of 24.2%, a significant 123.72% increase in overall PCE.