21.15%‐Efficiency and Stable γ ‐CsPbI 3 Perovskite Solar Cells Enabled by an Acyloin Ligand

Abstract Cesium lead triiodide (CsPbI 3 ) is a promising light‐absorbing material for constructing perovskite solar cells (PSCs) owing to its favorable bandgap and thermal tolerance. However, the high density of defects in the CsPbI 3 film not only act as recombination centers, but also facilitate ion migration, leading to lower PCE and inferior stability compared with the state‐of‐the‐art organic–inorganic hybrid PSC counterpart. Theoretical analyses suggest that the effective suppression of defects in CsPbI 3 film is helpful for improving the device performance. Herein, the stable and efficient γ ‐CsPbI 3 PSCs are demonstrated by developing an acyloin ligand (1,2‐di(thiophen‐2‐yl)ethane‐1,2‐dione (DED)) as a…

• NN
  National Natural Science Foundation of China

  Awards: 62074095, 62204148
• CP
  China Postdoctoral Science Foundation

  Award: 2022M711997
• HE
  Higher Education Discipline Innovation Project

  Award: B21005