All-inorganic CsPbX₃ perovskite quantum dots (QDs) are of great interest in the new-generation optoelectronic applications. However, the inferior long-term stability of CsPbX₃ QDs has severely hindered their real applications. In this paper, we have developed a simple and efficient in-situ guanidinium bromide (GABr) passivation approach to synthesize CsPbBr₃ QDs by introducing appropriate amount of GABr into the precursor solution using the traditional hot injection method. The in-situ GABr passivation treatment is demonstrated to effectively improve the crystallinity and regulate the grain size of CsPbBr₃ QDs without changing the crystal structure. More importantly, the in-situ GABr passivation treatment strategy can induce the passivation of surface defects and formation of the stable bromine-rich surface with tri-ligand mode. Consequently, the in-situ GABr passivated CsPbBr₃ QDs display remarkably improved optical properties and environmental stability. Additionally, the in-situ GABr passivated CsPbBr₃ QDs have been successfully employed in photodetectors and white light-emitting diodes (WLEDs), showing great practical application prospects. Our work may afford a new guideline to prepare CsPbBr₃ QDs with high photoluminescence and environmental Stability.

全无机CsPbX ₃钙钛矿量子点（QD）在新一代光电应用中引起了极大的兴趣。但是，CsPbX ₃ QD的较差的长期稳定性严重阻碍了它们的实际应用。在本文中，我们开发了一种简单有效的原位溴化胍鎓（GABr）钝化方法，通过使用传统的热注入方法将适量的GABr引入前体溶液中来合成CsPbBr ₃ QD。该原位GABR钝化处理被证明有效地提高了结晶度和调节CsPbBr的晶粒尺寸_3层的QD而不改变结晶结构。更重要的是原位GABr钝化处理策略可以通过三配体模式诱导表面缺陷的钝化并形成稳定的富含溴的表面。因此，原位GABr钝化的CsPbBr ₃ QDs显着改善了光学性能和环境稳定性。此外，原位GABr钝化的CsPbBr ₃ QD已成功用于光电探测器和白光发光二极管（WLED），显示出巨大的实际应用前景。我们的工作可能会为制备具有高光致发光和环境稳定性的CsPbBr ₃ QD提供新的指导方针。