A cost-effective multifunctional molecule for efficient and stable invert perovskite solar cells

Perovskite solar cells (PSCs) face critical challenges in achieving commercial viability, primarily due to interfacial defects that induce non-radiative recombination and environmental instability. To address these limitations, this study introduces tris(1-chloro-2-propyl) phosphate (TCPP) as a cost-effective multifunctional interfacial modifier. The P=O groups in TCPP exhibit strong Lewis basicity, enabling dual defect passivation via coordination with undercoordinated Pb²⁺ ions. Density functional theory (DFT) calculations demonstrate its efficacy in eliminating deep-level trap states (Pb clusters) and repairing shallow defects (I vacancies), as evidenced by normalized density of states resembling ideal perovskite. Experimental validation shows remarkable performance enhancements: optimized devices achieve a champion PCE of 20.73% (vs. 18.83% control). These synergistic improvements underscore TCPP’s multifunctionality in balancing efficiency, stability, and scalability. The work provides a viable pathway for commercial perovskite photovoltaics, with future research directions extending to diverse perovskite compositions and large-area fabrication protocols.