Intermediate Phase Engineering with 2,2‐Azodi(2‐Methylbutyronitrile) for Efficient and Stable Perovskite Solar Cells

• DOI: 10.1002/adma.202210186
• Publication Date: 2023-03-24T14:13:27Z
• Authors: Yansong Ge; Haibing Wang; Cheng Wang; Chen Wang; Hongling Guan; Wenlong Shao; Ti Wang; Weijun Ke; Chen Tao; Guojia Fang
• Keywords: Passivation

Sequential deposition has been widely employed to modulate the crystallization of perovskite solar cells because it can avoid formation nucleation centers and even initial in precursor solution. However, challenges remain overcoming incomplete random transformation PbI2 films with organic ammonium salts. Herein, a unique intermediate phase engineering strategy developed by simultaneously introducing 2,2-azodi(2-methylbutyronitrile) (AMBN) both salt solutions regulate crystallization. AMBN not only coordinates form favorably mesoporous film due coordination between Pb2+ cyano group (C≡N), but also suppresses vigorous activity FA+ ions interacting FAI, leading full preferred orientation. Therefore, perovskites favorable facet orientations are obtained, defects largely suppressed owing passivation uncoordinated . As result, champion power conversion efficiency over 25% stabilized 24.8% is achieved. Moreover, device exhibits an improved operational stability, retaining 96% under 1000 h continuous white-light illumination intensity 100 mW cm-2 at ≈55 °C N2 atmosphere.