Liu Lige, Dong Dashan, Long Zhiwei, Wei Wanxue, Sun Chang, Liu Wei, Huang Xiaoshuai, Chen Liangyi, Zhong Haizheng, Shi Kebin
State Key Laboratory of Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China.
Nat Commun. 2025 Jul 1;16(1):5664. doi: 10.1038/s41467-025-60826-x.
Because of the lack of spatiotemporal characterization techniques, it has been of great challenge to investigate the crystallization of nanocrystals. With a high-speed structured illumination super-resolution fluorescence microscopy (SIM), we hereby report an in situ fluorescence imaging technique to monitor the crystallization of perovskite nanocrystals at single-particle level. By correlating the fluorescence intensity with particle size, we illustrate the coupled nucleation-and-growth of perovskite nanocrystals in polymer matrix. The temporal fluorescence intensity analysis of individual nanocrystals reveals the diffusion-controlled growth process with a fast growth at the beginning followed by a slow growth. The analysis of ensemble nanocrystals illustrates the evolution of nucleation rate with the change of precursor concentrations. We further analyze the Gibbs free energy fluctuation of couple nucleation-and-growth. The growth free energy dominates in the continuous nucleation of perovskite nanocrystals, which accounts for the narrow size distribution. In comparison with LaMer model, the coupled nucleation-and-growth provides an alternative model to fabricate narrow sized nanocrystals.
由于缺乏时空表征技术，研究纳米晶体的结晶过程面临巨大挑战。借助高速结构光照超分辨率荧光显微镜（SIM），我们在此报告一种原位荧光成像技术，用于在单粒子水平监测钙钛矿纳米晶体的结晶过程。通过将荧光强度与粒径相关联，我们阐明了钙钛矿纳米晶体在聚合物基质中的成核与生长耦合过程。对单个纳米晶体的时间荧光强度分析揭示了扩散控制的生长过程，即开始时快速生长，随后缓慢生长。对整体纳米晶体的分析表明了成核速率随前驱体浓度变化的演变情况。我们进一步分析了成核与生长耦合的吉布斯自由能波动。生长自由能在钙钛矿纳米晶体的连续成核中占主导地位，这解释了其窄尺寸分布。与拉默模型相比，成核与生长耦合提供了一种制备窄尺寸纳米晶体的替代模型。
