Fluorine Functionalized MXene QDs for Near‐Record‐Efficiency CsPbI3 Solar Cell with High Open‐Circuit Voltage

• Published in: Advanced functional materials Vol. 32; no. 33
• Main Authors: Xu, Dongfang, Li, Tong, Han, Yu, He, Xuexia, Yang, Shaomin, Che, Yuhang, Xu, Jie, Zou, Hong, Guo, Xi, Wang, Jungang, Lei, Xuruo, Liu, Zhike
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.08.2022
• Subjects: Barrier layers; Circuits; Efficiency; Electric potential; Energy levels; Fluorine; high efficiency; high voltages; inorganic perovskites; Materials science; MXenes; Perovskites; Photovoltaic cells; Quantum dots; Solar cells; Thermal stability; Ti 3C 2F x QDs; Voltage
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202203704

CsPbI3 inorganic perovskites have attracted significant attention due to their desirable bandgap for tandem solar cells and excellent thermal stability. However, CsPbI3 perovskite solar cells (PSCs) still exhibit low efficiency and high energy loss due to nonradiative recombination. Herein, functionalized Ti3C2Fx quantum dots (QDs) are prepared and selected as interface passivators to enhance the performance of CsPbI3 PSCs. The systematic experimental results reveal that Ti3C2Fx QDs serve as effective passivators mainly in three aspects: 1) p‐type Ti3C2Fx QDs can tune the energy level of perovskite films and provide an efficient pathway for hole transfer; 2) Ti3C2Fx QDs can effectively passivate defects and reduce interfacial nonradiative recombination, and 3) Ti3C2Fx QDs form a barrier layer to prevent water invasion and improve the stability of CsPbI3 PSCs. Consequently, the champion CsPbI3 PSC with Ti3C2Fx QDs treatment exhibits an excellent efficiency of 20.44% with a high open‐circuit voltage of 1.22 V. Meanwhile, the corresponding device without encapsulation retained 93% of its initial efficiency after 600 h of storage in ambient air. Herein, Ti3C2Fx quantum dots are prepared and selected as interfacial passivators to enhance the performance of CsPbI3 perovskite solar cells (PSCs), which can tune the energy level, passivate defects, and form barrier layers for CsPbI3 film. Consequently, CsPbI3 PSC with an efficiency of 20.44% is obtained, which retains 93% of its initial efficiency after 600 h aging in ambient air without encapsulation.