Cao Jingjing, Wang Qungui, Li Wen, Yan Cheng, Zeng Xiankan, Gao Yue, Zheng Xiaotong, Lu Jun, Yang Weiqing
Key Laboratory of Advanced Technologies of Materials (Ministry of Education),School of Materials Science and Engineering, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, PR China.
Key Laboratory of Advanced Technologies of Materials (Ministry of Education),School of Materials Science and Engineering, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, PR China.
J Colloid Interface Sci. 2022 Nov 15;626:591-598. doi: 10.1016/j.jcis.2022.06.170. Epub 2022 Jul 3.
Hydrogen bromide (HBr) could substantially improve the quality of cesium lead bromide perovskite (CsPbBr) nanocrystals (NCs) and greatly enhance their optoelectronic performance. However, clarifying the role of HBr in the growth of CsPbBr NCs has been a substantial challenge thus far. Herein, we design an in situ cryogenic photoluminescence system using liquid nitrogen to unravel the role played by HBr in the growth of CsPbBr NCs. Compared with no HBr (∼40 s), HBr improves the nucleation rate of CsPbBr NCs about two times (∼20 s), and its emission peak also exhibits a redshift of ∼30 nm. Thus, we conclude that HBr accelerates the nucleation rate of CsPbBr NCs and extends their growth stage, affording the generation of large grains. Perovskite light-emitting diodes based on CsPbBr NCs with added HBr also exhibit an outstanding performance. These outcomes provide new insights into the role of HBr in CsPbBr NCs and help prepare high-quality CsPbBr NCs for use in the fabrication of efficient CsPbBr NC-based optoelectronic devices.
溴化氢（HBr）能够显著提高溴化铯铅钙钛矿（CsPbBr）纳米晶体（NCs）的质量，并极大地增强其光电性能。然而，迄今为止，阐明HBr在CsPbBr NCs生长过程中的作用一直是一项重大挑战。在此，我们设计了一种使用液氮的原位低温光致发光系统，以揭示HBr在CsPbBr NCs生长过程中所起的作用。与不添加HBr时（约40秒）相比，HBr使CsPbBr NCs的成核速率提高了约两倍（约20秒），并且其发射峰还呈现出约30纳米的红移。因此，我们得出结论，HBr加速了CsPbBr NCs的成核速率并延长了它们的生长阶段，从而生成了大晶粒。基于添加了HBr的CsPbBr NCs的钙钛矿发光二极管也表现出出色的性能。这些结果为HBr在CsPbBr NCs中的作用提供了新的见解，并有助于制备高质量的CsPbBr NCs，用于制造高效的基于CsPbBr NCs的光电器件。
