25.24%‐Efficiency FACsPbI 3 Perovskite Solar Cells Enabled by Intermolecular Esterification Reaction of DL‐Carnitine Hydrochloride

Abstract Judicious tailoring of the interface between the SnO 2 electron‐transport layer and the perovskite buried surface plays a pivotal role in obtaining highly efficient and stable perovskite solar cells (PSCs). Herein, a DL‐carnitine hydrochloride (DL) is incorporated into the perovskite/SnO 2 interface to suppress the defect‐states density. A DL‐dimer is obtained at the interface by an intermolecular esterification reaction. For the SnO 2 film, the Cl − in the DL‐dimer can passivate oxygen vacancies (V O ) through electrostatic coupling, while the N in the DL‐dimer can coordinate with the Sn 4+ to passivate Sn‐related defects. For the perovskite film, the DL‐dimer can passivate FA + defects via hydrogen…

• NN
  National Natural Science Foundation of China

  Awards: B21005, 62074095, 62204148, DNL180311
• CP
  China Postdoctoral Science Foundation

  Award: 2022M711997
• HE
  Higher Education Discipline Innovation Project

  Awards: DNL180311, B21005
• KR
  Key Research and Development Projects of Shaanxi Province

  Award: 2022LL-JB-08