Interface engineering with aromatic silane carbonates toward efficient and durable perovskite photovoltaics

Perovskite solar cells (PSCs) have achieved impressive efficiency gains; however, instability and interfacial defects stand in the way of commercialization. In this paper, we report a new molecular interfacial modifier, 4-Nitrophenyl 2-(Trimethylsilyl)ethyl Carbonate (NPTSEC), which simultaneously improves the device efficiency and stability. Through Lewis-base coordination, the carbonate group in NPTSEC binds undercoordinated Pb 2+ ions, as supported by DFT calculations, thereby passivating trap states and reducing non-radiative recombination, while the hydrophobic trimethylsilyl unit protects against moisture penetration and interfacial degradation. This dual-functional modification results in an improved film morphology, optimized interfacial energy alignment, and efficient charge extraction with minimal hysteresis. Consequently, the device delivered a power conversion efficiency (PCE) of 21.2% and retained over 90% of its initial output after 1170 h under ambient conditions, demonstrating pronounced long-term stability. • NPTSEC provides dual-function passivation by reducing Pb 2+ defects and improving moisture resistance. • It enhances film quality, suppresses recombination, and promotes efficient charge extraction. • NPTSEC-treated PSCs deliver a high-power conversion efficiency of 21.2%. • The devices show excellent stability, retaining 90% efficiency after1170 hours of ambient aging.