Stabilizing initial phase for efficient and stable FAPbI3 perovskite solar cells

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 500; p. 156803
• Main Authors: Guo, Junxue, Liu, Yang, Chi, Haibo, Zhou, Bo, Liu, Xiaotao, Guo, Xin, Yu, Wei, Li, Can
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2024
• Subjects: 0D perovskite; 0D/3D mixed perovskites; Initial phase; Residual PbI2; α-FAPbI3; Residual PbI2; 0D/3D mixed perovskites; Initial phase; 0D perovskite; α-FAPbI3
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156803

The addition of 0D perovskite reduces defect density and forms a mixed 0D/3D perovskite in the bulk, thereby stabilizing the initially formed α-FAPbI3 phase. This effectively retards perovskite decomposition, leading to a reduction in residual PbI2. Consequently, the 0D perovskite-decorated PSCs demonstrate enhanced efficiency and stability. [Display omitted] •The 0D perovskite-decorated strategy enhances the intrinsic stability of FAPbI3 by stabilizing the initial α-FAPbI3 phase.•The 0D perovskites effectively retards FAPbI3 decomposition, leading to a decrease in residual PbI2.•The 0D-treated device endows significant enhancement in both PCE (from 22.23% to 24.56%) and device stability. Formamidinium lead triiodide (FAPbI3) perovskite stands at the forefront of efficiency in perovskite solar cells (PSCs), yet the thermodynamically unstable α-phase poses a challenge to device long-term stability. While thermal annealing is essential for producing high-quality polycrystalline films that stabilize the α-FAPbI3 phase, it also induces partial decomposition of FAPbI3 into PbI2, leading to extra phase instability of FAPbI3 films. Here, we develop a zero dimensional (0D) perovskite-decorated strategy to enhance the intrinsic stability of FAPbI3 film by stabilization of the initially formed α-FAPbI3 phase. This is achieved by reducing the defect density and forming mixed 0D/3D perovskites, which effectively slow down perovskite decomposition during thermal annealing and decrease the amount of residual PbI2 in the final film. The reduced trap density in 0D perovskite-treated PSCs suppresses Shockley-Read-Hall nonradiative recombination and improves charge collection efficiency. Consequently, the 0D perovskite-decorated PSCs endow significant enhancements in both power conversion efficiency (from 22.23% to 24.56%) and device stability. This novel 0D perovskite-decorated strategy offers a promising path toward more robust PSCs.