Xu Peng, Wang Pengfei, Wang Minhuan, Sun Fengke, Leng Jing, Shi Yantao, Jin Shengye, Tian Wenming
Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
State Key Laboratory of Chemical Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China.
Nanomicro Lett. 2025 Jun 4;17(1):285. doi: 10.1007/s40820-025-01795-0.
Historically seen as a limitation, grain boundaries (GBs) within polycrystalline metal halide perovskite (MHP) films are thought to impede charge transport, adversely impacting the efficiency of perovskite solar cells (PSCs). In this study, we employ home-built confocal photoluminescence microscopy, combined with photocurrent detection modules, to directly visualize the carrier dynamics in the MHP film of PSCs under real operating conditions. Our findings suggest that GBs in high-efficiency PSCs function as carrier transport channels, where a notable enhancement in photocurrent is observed. Femtosecond transient absorption and Kelvin probe force microscopy measurements further validate the existence of a built-in electric field in the vicinity of GBs, offering additional driving force for charge separation and establishing channels for swift carrier transport along the GBs, thereby expediting subsequent charge collection processes. This study elucidates the pivotal role of GBs in operational PSCs and provides valuable insights for the fabrication of high-efficiency PSCs.
从历史上看，多晶金属卤化物钙钛矿（MHP）薄膜中的晶界（GBs）被视为一种限制因素，人们认为它会阻碍电荷传输，对钙钛矿太阳能电池（PSC）的效率产生不利影响。在本研究中，我们采用自制的共聚焦光致发光显微镜，并结合光电流检测模块，在实际工作条件下直接观察PSC的MHP薄膜中的载流子动力学。我们的研究结果表明，高效PSC中的GBs起到载流子传输通道的作用，在那里观察到光电流有显著增强。飞秒瞬态吸收和开尔文探针力显微镜测量进一步证实了GBs附近存在内建电场，为电荷分离提供了额外的驱动力，并为载流子沿GBs快速传输建立了通道，从而加速了后续的电荷收集过程。本研究阐明了GBs在工作PSC中的关键作用，并为高效PSC的制造提供了有价值的见解。
