Qiu Junming, Mei Xinyi, Zhang Mingxu, Wang Guoliang, Pan Lixin, Zou Shenwen, Huang Jianmei, Zhang Xiaoliang
School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
School of Energy and Power Engineering, Beihang University, Beijing, 100191, China.
Angew Chem Int Ed Engl. 2025 Jul 21;64(30):e202506282. doi: 10.1002/anie.202506282. Epub 2025 May 24.
Inorganic CsPbI perovskite attracts widespread attention in photovoltaic applications due to its superior thermal stability and optoelectronic properties. However, CsPbI perovskite solar cells (PSCs) still suffer from severe energy losses due to interface nonradiative recombination and undesirable charge carrier transfer, predominantly limiting their photovoltaic performance. Herein, an interfacial dipole engineering is introduced for CsPbI PSCs, in which azetidinium chloride (Az) and its fluorinated derivative 3,3-difluoroazetidinium chloride (DFAz) are employed to manipulate the interface properties of PSCs and thus diminish energy losses. Systematically theoretical calculations and experimental studies reveal that the fluorination-assisted ammonium molecule could form a stronger interaction with perovskites and thereby arrange the dipole alignment on the superficial layer of perovskites, which could simultaneously ameliorate the passivation effect and energy level alignment of the perovskite and hole transport layers, thereby suppressing interface recombination. Meanwhile, the coordinated bonding between the ammonium and hole transport layer facilitates charge transfer at the heterojunction interface by offering additional carrier transport channels. Consequently, the CsPbI PSCs deliver a high efficiency of up to 22.05%. This work provides important design principles of interface engineering for high-performance solar cells to minimize energy losses.
无机CsPbI钙钛矿因其优异的热稳定性和光电性能在光伏应用中受到广泛关注。然而，CsPbI钙钛矿太阳能电池（PSCs）仍因界面非辐射复合和不理想的电荷载流子转移而存在严重的能量损失，这主要限制了它们的光伏性能。在此，我们为CsPbI PSCs引入了界面偶极工程，其中使用氮杂环丁烷氯化物（Az）及其氟化衍生物3,3 - 二氟氮杂环丁烷氯化物（DFAz）来调控PSCs的界面性质，从而减少能量损失。系统的理论计算和实验研究表明，氟化辅助的铵分子能与钙钛矿形成更强的相互作用，进而排列钙钛矿表层的偶极取向，这可以同时改善钙钛矿与空穴传输层的钝化效果和能级匹配，从而抑制界面复合。同时，铵与空穴传输层之间的配位键通过提供额外的载流子传输通道促进了异质结界面处的电荷转移。因此，CsPbI PSCs实现了高达22.05%的高效率。这项工作为高性能太阳能电池提供了重要的界面工程设计原则，以尽量减少能量损失。
