Abstract
It's still a scientific issue to synthesize exotic amines-free and pure-phase FAPbI3 film because most FAPbI3 films are synthesized by adding MACl-like exotic amines salts in their precursor solution to reduce the phase transition barrier. In this work, high-quality and additive-free phase-pure α-FAPbI3 films are successfully fabricated via the sustainable Alkane/Nanocrystals method. FAPbI3 nanocrystals (NCs) are performed as the heterogeneous nuclei to promote the nucleation and crystallization of FAPbI3 films. Cryogenic-TEM and in situ GIWAXS evidence the seed function and interesting phase evolution of FAPbI3 NCs. The whole phase transition course of pure FAPbI3 film is systematically studied. IR-AFM and ToF-SIMS reveal ligands capped on NCs are extruded to the film surface. PbAc-IPA solution treating the film surface can effectively wash off the surplus ligands at the surface and modulate the surface chemistry and energy levels. As a result, an average power conversion efficiency (PCE) of 21.45% is achieved for MA-free pure α-FAPbI3 perovskite solar cells (PSCs), as well as the best light-soaking stability record of retaining 95% of the initial PCE after 800 h. This work paves a new way to fabricate MA-free pure α-FAPbI3 PSCs.
Original language | English |
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Article number | 2402024 |
Journal | Advanced Functional Materials |
Early online date | 18 Apr 2024 |
DOIs | |
Publication status | E-pub ahead of print - 18 Apr 2024 |
Keywords
- FAPbI3
- interface
- MA-free
- nanocrystals seeded growth
- perovskite solar cell