题目：Unlocking the Full Potential of Graded-Bandgap Engineering for Efficient and Stable Perovskite Solar Cells: Mechanism Insights and Performance Optimization
作者：Yu Cao1,2, Yuqi Zhang1,2, Yining Bao1,2, Luolei Shi1,2, Guoyang Cao1,2,3,*, Linling Qin1,2,*, Changlei Wang1,2, Xiaofeng Li1,2,*, and Zhenhai Yang1,2,*
单位：
1 School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
2 Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
3 Engineering Research Center of Digital Graphic and Next-Generation Printing, Jiangsu Province, Soochow University, Suzhou 215006, China
Abstract: For perovskite solar cells (PSCs), suppressing non-radiative recombination losses at the perovskite interfaces is crucial, one effective strategy is the intentional introduction of a graded perovskite bandgap configuration. However, designing such a structure to unlock its potential in PSCs remains a challenge. In this work, we conduct a comprehensive numerical simulation study to elucidate the physical mechanisms underlying graded-bandgap designs and explore their potential for efficient and stable PSCs. All results are based on systematic device-level simulations, providing a theoretical foundation for guiding experimental implementation. Our results demonstrate that introducing a tailored graded perovskite bandgap configuration featuring a high bandgap gradient and shallow graded-bandgap depth effectively suppresses interfacial recombination through the combined effects of interfacial energy band bending and reduced minority carrier concentration. Notably, PSCs featuring a double-sided graded perovskite bandgap exhibit a significant enhancement in open-circuit voltage and achieve a remarkable efficiency exceeding 27%. Furthermore, the graded-bandgap design demonstrates high tolerance to variations in energy band offset, interface and perovskite bulk defect density. Although this design amplifies bulk defects' impact on carrier transport, it can simultaneously mitigate current hysteresis by suppressing ion migration behavior. Moreover, we confirm that graded-bandgap structures offer performance comparable to or even superior to that of widely used 2D/3D heterostructures, highlighting the advantages of graded-bandgap engineering in designing efficient and stable PSCs.
摘要：对于钙钛矿太阳能电池而言，抑制钙钛矿界面的非辐射复合至关重要，其中一种有效的策略是引入渐变钙钛矿带隙结构。然而，采用这种结构制备高效钙钛矿太阳能电池仍然存在较大的挑战。在这个工作中，我们采用全面的数值仿真阐明了渐变带隙结构设计的物理机制，并探索了它们在高效稳定的钙钛矿太阳能电池中的应用潜力。呈现的结果均基于系统的器件级仿真，为指导实验制备提供了理论基础。我们的结果显示：引入具有高带隙和浅深度的渐变钙钛矿带隙结构可以通过界面能带弯曲和降低少数载流子浓度，有效地抑制界面复合。具有双面渐变钙钛矿带隙的钙钛矿太阳能电池对开路电压具有显著的增强作用，可达到27%的理论效率。此外，渐变带隙设计对能带偏移、界面和钙钛矿体缺陷密度有较大的容忍度。尽管这种设计放大了体缺陷对载流子传输的影响，但它可以通过抑制离子迁移行为减轻电流迟滞行为。此外，我们证实渐变带隙结构的性能可与广泛使用的二维/三维异质结构相媲美，突显了渐变带隙工程在设计高效稳定钙钛矿太阳能电池方面的优势。
影响因子：16.8
链接：//doi.org/10.1016/j.nanoen.2025.111228