取代型多金属氧酸盐修饰的SnO₂用于增强界面接触以实现高效碳基全无机钙钛矿太阳能电池

Abstract SnO 2 demonstrates three critical characteristics for photovoltaic applications, low temperature preparation process, high conductivity and high ultraviolet light stability. These superiorities makes it a preferred choice for high-performance perovskite solar cells (PSCs) as a charge transport material. However, PSCs based on SnO 2 still faces great challenges. Poor interface contact and interface defects are important factors for loss of efficiency and long-term stability. This study demonstrates a synergistic interface engineering in all-inorganic CsPbI 2 Br solar cells through strategic integration of transition-metal substituted Keggin-type polyoxometalates K 6 H 4 [SiW 9 O 37 {Ni(H 2 O)} 3 ({SiW 9 Ni 3 }) with SnO 2 quantum dots. The SnO 2 @SiW 9 Ni 3 composite electron transport layer boosts electrical conductivity through enhanced electron mobility channels. {SiW 9 Ni 3 } can also passivate interfacial defects via strong chemical bonding between terminal oxygens and undercoordinated Sn 4+ and reduce oxygen vacancy defects, effectively suppressing non-radiative recombination. Additionally, perovskite crystallization can be regulated by metal–oxygen coordination, which result in a pinhole-free and high quality film based on SnO 2 @SiW 9 Ni 3 . The target devices achieve a champion PCE of 13.09 % (vs. 10.75 % control) with a remarkable open-circuit voltage ( V OC ) enhancement from 1.256 V to 1.301 V. At the same time, the optimized devices retain over 90 % initial efficiency after 600 h ambient aging, demonstrating prominent operational stability. This work establishes a polyoxometalate-driven interfacial engineering strategy for advancing high-performance all-inorganic perovskite solar cells.