Akademik Veri Yönetim Sistemi
Journal of Materials Chemistry C, 2026 (SCI-Expanded, Scopus)
Suppressing nonradiative recombination induced by surface and grain-boundary defects remains a central challenge for achieving high efficiency and long-term stability in formamidinium lead iodide (FAPbI3) perovskite solar cells (PSCs). Here, we introduce an ester-functionalized quinquephenyl molecule, Ph5-(COOCH3)6, as an effective molecular passivation agent for FAPbI3 perovskite films. By systematically tuning the concentration of Ph5-(COOCH3)6 deposited atop the perovskite absorber, we demonstrate pronounced improvements in both optoelectronic quality and device performance. Structural and spectroscopic analyses reveal that Ph5-(COOCH3)6 passivation preserves the crystalline integrity of FAPbI3 while inducing favorable surface electronic modifications, evidenced by an upward shift in surface potential, reduced energetic disorder, and suppressed trap-assisted recombination. Consequently, Ph5-(COOCH3)6-treated films exhibit prolonged carrier lifetimes, reduced trap densities, and improved charge transport characteristics. Devices incorporating an optimal Ph5-(COOCH3)6 concentration (2 mg mL−1) achieve a champion power conversion efficiency (PCE) of 23.13% with an average efficiency of 22.86 ± 0.19%, accompanied by simultaneous enhancements in all photovoltaic parameters. Moreover, Ph5-(COOCH3)6 passivated PSCs display markedly improved operational stability, retaining ∼94.4% of their initial efficiency after 1000 h of aging without encapsulation, compared to severe degradation in control devices. This work highlights the potential of ester-based π-conjugated molecular passivation as a versatile strategy for addressing stability and efficiency limitations by mitigating open-circuit voltage (VOC) losses.