Zhang Xue, Cui Yanyu, Ye Siyuan, Lin Zhuohan, Li Yan
Key Laboratory for Advanced Materials, Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
Key Laboratory for Advanced Materials, Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Colloid Interface Sci. 2024 Aug 15;668:68-76. doi: 10.1016/j.jcis.2024.03.202. Epub 2024 Mar 30.
Two-dimensional (2D) CsPbBr nanoplatelets (NPLs) have attracted great attention as one of promising semiconductor nanomaterials due to their large exciton binding energy and narrow emission spectra. However, the labile ionic and weakly bound surfaces of deep-blue emitting CsPbBr NPLs with wide bandgap result in their colloidal instability, thus degrading their optical properties. It is challenging to obtain deep-blue emitting CsPbBr NPLs with excellent optical properties. In this study, high-quality blue-emitting CsPbBr NPLs with tunable thickness were prepared adopting the DBSA-mediated confinement effect based on the hot-injection method. Thanks to the coordination interaction of - SO of DBSA ligand and the Pb on the surface of the CsPbBr NPLs, as well as the effective passivation of Br vacancy defects on the surface of NPLs by OAm-Br, the obtained pure-blue CsPbBr NPLs and deep-blue CsPbBr NPLs show high photoluminescence quantum yield (PLQY) of 92 % and 81.2 %, respectively. To the best of our knowledge, this is the highest PLQY recorded for deep-blue emitting CsPbBr NPLs with two monolayers [PbBr] octahedra. Furthermore, the agglomeration of CsPbBr NPLs due to ligand loss induced by moisture, oxygen, and irradiation was also suppressed by the dual passivation effect of DBSA and OAm-Br. Our work provided a new approach to developing high-performance and stable deep-blue emitting CsPbBr perovskite nanoplatelets.
二维（2D）CsPbBr纳米片（NPLs）因其具有大的激子结合能和窄的发射光谱，作为一种有前途的半导体纳米材料而备受关注。然而，具有宽带隙的深蓝色发射CsPbBr NPLs的不稳定离子和弱结合表面导致其胶体不稳定性，从而降低其光学性能。获得具有优异光学性能的深蓝色发射CsPbBr NPLs具有挑战性。在本研究中，基于热注入法采用DBSA介导的限制效应制备了厚度可调的高质量蓝色发射CsPbBr NPLs。由于DBSA配体的-SO与CsPbBr NPLs表面的Pb之间的配位相互作用，以及OAm-Br对NPLs表面Br空位缺陷的有效钝化，所获得的纯蓝色CsPbBr NPLs和深蓝色CsPbBr NPLs分别显示出92%和81.2%的高光致发光量子产率（PLQY）。据我们所知，这是具有两个单层[PbBr]八面体的深蓝色发射CsPbBr NPLs所记录的最高PLQY。此外，DBSA和OAm-Br的双重钝化作用也抑制了由于水分、氧气和辐照引起的配体损失导致的CsPbBr NPLs的团聚。我们的工作为开发高性能和稳定的深蓝色发射CsPbBr钙钛矿纳米片提供了一种新方法。
