Lead halide perovskite CsPbBr₃ nanocrystals (NCs) have attracted great interest in recent years owing to their excellent properties such as strong light absorption, high photoluminescence quantum yield (PLQY), good wavelength tunability, and narrow FWHM. However, their instability is still a bottleneck for their potential application. In this work, a pseudo-peritectic method, which is a peritectic reaction in solutions, was proposed. The phenomenon of “Survival of the fittest” was observed. The synthesized CsPb₂Br₅ phase greatly reduces the surface defects, and improves the stability and PL properties. The pseudo-peritectic method using for preparing surface modified CsPbBr₃@CsPb₂Br₅ nanocrystals is a significant pathway to achieve long-term stable lead halide perovskite for optoelectronic devices.

近年来，卤化钙钛矿型CsPbBr ₃纳米晶体（NCs）吸引了人们的兴趣，因为它们具有诸如强光吸收，高光致发光量子产率（PLQY），良好的波长可调性和窄的FWHM之类的优异性能。但是，它们的不稳定性仍然是其潜在应用的瓶颈。在这项工作中，提出了一种伪包晶方法，它是溶液中的包晶反应。观察到“适者生存”现象。合成的CsPb ₂ Br ₅相大大降低了表面缺陷，并提高了稳定性和PL性能。用于制备表面改性的CsPbBr ₃ @CsPb ₂ Br ₅的拟包晶方法 纳米晶体是实现用于光电器件的长期稳定的卤化钙钛矿的重要途径。