CsPbBr₃ perovskite nanocrystals (mainly nanoplatelet morphology) have attracted attention due to their promising applications in optoelectronic devices. However, ultraviolet (UV) light exposure to these materials is one of the major factors for the degradation of halide perovskite nanocrystals, which needs to be studied to improve stability and boost performance. In this study, we synthesized CsPbBr₃ perovskite nanoplatelets utilizing a hot injection method. The UV illumination effect on luminescence and structural properties of perovskite CsPbBr₃ nanoplatelets were studied in detail. Under UV light illumination, less-emissive phases like CsPb₂Br₅ were observed within 10 h. However, long-term (i.e., 48 h) illumination of UV light resulted in the formation of some trace of PbCO₃ and PbO phases that causes further degradation of perovskite CsPbBr₃ nanoplatelets. This was verified by a significant decrease in photoluminescence (PL) intensity. Interestingly, UV light treated samples exhibited a stable CsPb₂Br₅ phase, which was observed after aging for a long period (∼9 months) of time that showed no further degradation. Furthermore, X-ray diffraction and full-width half maxima results confirmed an increase in crystalline size with illumination time increase. Obtained results strongly indicate that the UV light-induced PL degradation and trap state formation causes a synergistic effect of photo annealing in the presence of oxygen and moisture.

CsPbBr ₃钙钛矿纳米晶体（主要是纳米片形态）因其在光电器件中的应用前景而备受关注。然而，紫外线 (UV) 暴露于这些材料是卤化物钙钛矿纳米晶体降解的主要因素之一，需要对其进行研究以提高稳定性和提高性能。在这项研究中，我们利用热注射法合成了 CsPbBr ₃钙钛矿纳米片。详细研究了紫外线照射对钙钛矿 CsPbBr ₃纳米片的发光和结构特性的影响。在紫外光照射下，CsPb ₂ Br ₅等低发射相10 小时内观察到。然而，长期（即，48 小时）紫外线照射导致形成一些痕量的 PbCO ₃和 PbO 相，从而导致钙钛矿 CsPbBr ₃纳米片的进一步降解。光致发光 (PL) 强度的显着降低证实了这一点。有趣的是，经过紫外光处理的样品表现出稳定的 CsPb ₂ Br ₅阶段，这是在老化很长一段时间（约 9 个月）后观察到的，没有进一步降解。此外，X 射线衍射和半峰全宽结果证实了晶体尺寸随着光照时间的增加而增加。获得的结果强烈表明，紫外光诱导的 PL 降解和陷阱态形成导致在氧气和水分存在下光退火的协同效应。