Researchers from the University of Science and Technology of China and Hefei University of Technology have developed a proof-of-concept tandem solar cell tandem solar cell by using antimony selenide (Sb2Se3) for the bottom cell and a wide-bandgap organic-inorganic hybrid perovskite material for the top cell. The device reached a power conversion efficiency of more than 20%, which demonstrates that antimony selenide has a high potential for bottom-cell applications.
Antimony selenide (Sb2Se3) possesses a band gap of 1.05–1.2 eV and has been widely applied in single-junction solar cells. Based on its band gap, Sb2Se3 can also be used as the bottom cell absorber material in tandem solar cells. Sb2Se3-based solar cells also exhibit excellent stability with nontoxic compositional elements. In this recent work, the team demonstrated a perovskite/antimony selenide four-terminal tandem solar cell with a specially designed and fabricated transparent electrode for an optimized spectral response.
By adjusting the thickness of the transparent electrode layer of the top cell, the wide-band-gap perovskite top solar cell achieved an efficiency of 17.88%, while the optimized antimony selenide bottom cell delivered a power conversion efficiency of 7.85% by introducing a double electron transport layer. Finally, the four-terminal tandem solar cell achieved an impressive efficiency exceeding 20%.
Looking ahead, the team intends to develop a more integrated two-terminal tandem solar cell and enhance device performance.
