Chen Yanfeng, Nan Meng, He Yanxing, Lu Shuang, Shen Wei, Cheng Gang, Chen Shufen, Huang Wei
State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR China.
ACS Appl Mater Interfaces. 2024 May 1;16(17):22139-22146. doi: 10.1021/acsami.4c01824. Epub 2024 Apr 18.
During the synthesis of deep-blue perovskite quantum dots (PQDs), they generally emerge as a two-dimensional byproduct with poor yield and low photoluminescence quantum yield (PLQY) due to amine ligand enrichment-induced abundant surface defects. Herein, we provide a colloidal synthesis method to prepare deep-blue CsPbBr PQDs in a green nontoxic solvent via strategic Z-type ligand engineering. Z-type ligands of zinc octanoate enable the formation of robust coordination bonds with surface bromide ions of PQDs, maintaining acid-base equilibrium and reducing excess amine enrichment on the PQDs surface. Consequently, homogeneous and monodispersed PQDs with improved PLQY of 73% are successfully synthesized, achieving efficient deep-blue LEDs with a peak EQE of 5.46%, a maximum luminance of 847.6 cd/m, and an operational half-lifetime of 14 min. The devices exhibit color coordinates of (0.137, 0.049), closely approximating the Rec. 2020 blue standard. Our work offers a potentially eco-friendly and viable route for realizing high-performance LEDs in the deep-blue region.
在深蓝色钙钛矿量子点（PQDs）的合成过程中，由于胺配体富集导致大量表面缺陷，它们通常以二维副产物的形式出现，产率低且光致发光量子产率（PLQY）低。在此，我们提供一种胶体合成方法，通过策略性的Z型配体工程，在绿色无毒溶剂中制备深蓝色CsPbBr PQDs。辛酸锌的Z型配体能够与PQDs的表面溴离子形成牢固的配位键，维持酸碱平衡并减少PQDs表面过量的胺富集。因此，成功合成了PLQY提高到73%的均匀且单分散的PQDs，实现了高效深蓝色发光二极管，其峰值外量子效率（EQE）为5.46%，最大亮度为847.6 cd/m，工作半衰期为14分钟。这些器件的色坐标为（0.137, 0.049），非常接近Rec. 2020蓝色标准。我们的工作为在深蓝色区域实现高性能发光二极管提供了一条潜在的环保且可行的途径。
