Liu Bo-Chen, Lin Qizhong, Sun Shuang-Qiao, Sun Qi, Peng Xing, Chen Xinyuan, Li Yang, Xie Yue-Min, Lee Shuit-Tong, Fung Man-Keung
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China; Institute of Organic Optoelectronics (IOO), Jiangsu Industrial Technology Research Institute (JITRI), Suzhou 215200, China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China.
Sci Bull (Beijing). 2025 Mar 30;70(6):905-913. doi: 10.1016/j.scib.2025.01.017. Epub 2025 Jan 10.
High-quality quantum dots (QDs) possess superior electroluminescent efficiencies and ultra-narrow emission linewidths are essential for realizing ultra-high definition QD light-emitting diodes (QLEDs). However, the synthesis of such QDs remains challenging. In this study, we present a facile high-temperature successive ion layer adsorption and reaction (HT-SILAR) strategy for the growth of precisely tailored ZnCdSe/ZnSe shells, and the consequent production of high-quality, large-particle, alloyed red CdZnSe/ZnCdSe/ZnSe/ZnS/CdZnS QDs. The transitional ZnCdSe/ZnSe shells serve to effectively suppress heavy hole energy level splitting and weaken the exciton-longitudinal optical phonon coupling of QDs, thus facilitating the formation of highly luminescent QDs with a near-unity photoluminescence quantum yield of 97.8% and narrow emission with a full width at half maximum of 17.1 nm. In addition, the introduction of transitional shells can extend the particle size of QDs to 19.0 nm, which is beneficial for efficient carrier recombination and reduced Joule heating in QD-based LEDs. As a result, the fabricated QLEDs can achieve a record external quantum efficiency of 38.2%, luminance over 120,000 cd m, and exceptional operational stability T (tested at 1,000 cd m) of 24,100 h. These findings provide new avenues for synthesizing high-quality QDs with high color purity.
高质量量子点（QDs）具有卓越的电致发光效率，而超窄发射线宽对于实现超高清量子点发光二极管（QLEDs）至关重要。然而，此类量子点的合成仍然具有挑战性。在本研究中，我们提出了一种简便的高温连续离子层吸附与反应（HT-SILAR）策略，用于生长精确定制的ZnCdSe/ZnSe壳层，并由此制备出高质量、大尺寸、合金化的红色CdZnSe/ZnCdSe/ZnSe/ZnS/CdZnS量子点。过渡性的ZnCdSe/ZnSe壳层有助于有效抑制重空穴能级分裂，并减弱量子点的激子-纵向光学声子耦合，从而促进形成具有97.8%的近单位光致发光量子产率和半高宽为17.1 nm的窄发射的高发光量子点。此外，引入过渡性壳层可将量子点的粒径扩展至19.0 nm，这有利于基于量子点的发光二极管中载流子的高效复合并减少焦耳热。结果，所制备的QLED可实现创纪录的38.2%的外量子效率、超过120,000 cd m的亮度以及在1,000 cd m下测试的24,100 h的出色工作稳定性T。这些发现为合成具有高色纯度的高质量量子点提供了新途径。
