Cao Jiupeng, Liu Chun-Ki, Xu Yang, Loi Hok-Leung, Wang Tianyue, Li Mitch Guijun, Liu Lixian, Yan Feng
Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, 999077, P. R. China.
Division of Integrative Systems and Design, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, P. R. China.
Small. 2024 Nov;20(47):e2403920. doi: 10.1002/smll.202403920. Epub 2024 Aug 15.
Ideal bandgap (1.3-1.4 eV) Sn-Pb mixed perovskite solar cells (PSC) hold the maximum theoretical efficiency given by the Shockley-Queisser limit. However, achieving high efficiency and stable Sn-Pb mixed PSCs remains challenging. Here, piperazine-1,4-diium tetrafluoroborate (PDT) is introduced as spacer for bottom interface modification of ideal bandgap Sn-Pb mixed perovskite. This spacer enhances the quality of the upper perovskite layer and forms better energy band alignment, leading to enhanced charge extraction at the hole transport layer (HTL)/perovskite interface. Then, 2D TiCT MXene is incorporated for surface treatment of perovskite, resulting in reduced surface trap density and enhanced interfacial electron transfer. The combinations of double-sided treatment afford the ideal bandgap PSC with a high efficiency of 20.45% along with improved environment stability. This work provides a feasible guideline to prepare high-performance and stable ideal-bandgap PSCs.
理想带隙（1.3 - 1.4电子伏特）的锡铅混合钙钛矿太阳能电池（PSC）具有由肖克利 - 奎塞尔极限给出的最大理论效率。然而，实现高效率和稳定的锡铅混合PSC仍然具有挑战性。在此，引入哌嗪 - 1,4 - 二鎓四氟硼酸盐（PDT）作为理想带隙锡铅混合钙钛矿底部界面修饰的间隔层。该间隔层提高了上层钙钛矿层的质量并形成了更好的能带排列，从而增强了空穴传输层（HTL）/钙钛矿界面处的电荷提取。然后，引入二维TiCT MXene用于钙钛矿的表面处理，从而降低表面陷阱密度并增强界面电子转移。双面处理的组合提供了效率高达20.45%的理想带隙PSC，同时提高了环境稳定性。这项工作为制备高性能和稳定的理想带隙PSC提供了可行的指导方针。
