Chen Zhe-Yong, Ren Xue, Hu Hui-Ling, Liu Meng, Liu Yi, Jiang Feng-Lei
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China.
State Key Laboratory of Separation Membranes and Membrane Processes, School of Chemistry, Tiangong University, Tianjin 300387, P. R. China.
Phys Chem Chem Phys. 2024 Jun 19;26(24):17182-17190. doi: 10.1039/d4cp01109k.
ZnSeTe quantum dots (QDs) attract growing interest owing to their low threats to health and the environment. They are widely applied as emitters in displays and lighting devices. Previous findings have indicated that inorganic halides are excellent candidates for surface ligands on QDs. By incorporating inorganic halides during the synthesis process, the photoluminescence (PL) intensity and quantum yield (QY) of QDs can be significantly enhanced. However, the alteration of surface states in QDs induced by zinc halide modification and the mechanism of formation of trap-state radiative recombination processes have been less discussed. Herein, we proposed a synthesis strategy for ZnSeTe/ZnSe/ZnSeS/ZnS core/shell/shell/shell QDs modified with ZnCl, and by comparing the morphology and elemental composition of QDs with different amounts of ZnCl added, we revealed the regulatory mechanism of nanocrystal growth in the presence of ZnCl. QDs with modification of ZnCl exhibited broad yellow fluorescence, distinct from the intrinsic blue emission. Through spectroscopic and surface ligand analyses, we attributed this yellow emission to the intermediate state energy levels caused by the defects on the surface. Finally, we used the QDs with broad linewidth emission to fabricate a simple white-light-emitting diode (WLED). This work provided new insights into the role of inorganic ligands and the use of a single emitting material in solid-state lighting devices.
