Engineering Research Center for Nanophotonics & Advanced Instrument of Ministry of Education, Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, PR China.
Langmuir. 2023 May 2;39(17):6222-6230. doi: 10.1021/acs.langmuir.3c00393. Epub 2023 Apr 20.
Oleylamine/oleic acid (OAm/OA) as the commonly used ligand is indispensable in the synthesis of perovskite nanocrystals (PNCs). Unfortunately, poor colloidal stability and unsatisfactory photoluminescence quantum yield (PLQY) are observed, resulting from a highly dynamic binding nature between ligands. Herein, we adopt a facile hybrid ligand (DDAB/ZnBr) passivation strategy to reconstruct the surface chemistry of CsPbBr NCs. The hybrid ligand can detach the native surface ligand, in which the acid-base reactions between ligands are suppressed effectively. Also, they can substitute the loose capping ligand, anchor to the surface firmly, and supply sufficient halogens to passivate the surface trap, realizing an exceptional PLQY of 95% and an enhanced tolerance toward ambient storage, UV irradiation, anti-solvents, and thermal treatment. Besides, the as-fabricated white light-emitting diode (WLED) utilizing the PNCs as the green-emitting phosphor has a luminous efficiency around 73 lm/W; the color gamut covers 125% of the NTSC standard.
油胺/油酸（OAm/OA）作为常用配体，在钙钛矿纳米晶（PNCs）的合成中不可或缺。然而，由于配体之间具有高度动态的结合性质，导致其胶体稳定性差，光致发光量子产率（PLQY）不理想。在此，我们采用简便的混合配体（DDAB/ZnBr）钝化策略来重构 CsPbBr NCs 的表面化学。这种混合配体可以去除原有的表面配体，有效抑制配体之间的酸碱反应。此外，它们还可以取代松散的封端配体，牢固地锚定在表面上，并提供足够的卤素来钝化表面陷阱，实现了非凡的 PLQY 达到 95%，并提高了对环境储存、紫外光照射、抗溶剂和热处理的耐受性。此外，利用 PNCs 作为绿色发射磷光体制作的白色发光二极管（WLED）的光效约为 73 lm/W；色域涵盖 NTSC 标准的 125%。
