Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University and Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou 310024, China.
Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, School of Materials, Henan University, Kaifeng 475004, China.
Nano Lett. 2022 May 25;22(10):4067-4073. doi: 10.1021/acs.nanolett.2c00763. Epub 2022 May 10.
High-quality InP-based quantum dots (QDs) have become very promising, environmentally benign light emitters for display applications, but their synthesis generally entails hazardous hydrofluoric acid. Here, we present a highly facile route to InP/ZnSe/ZnS core/shell/shell QDs with a near-unity photoluminescence quantum yield. As the key additive, the inorganic salt ZnF mildly reacts with carboxylic acid at a high temperature and in situ generates HF, which eliminates surface oxide impurities, thus facilitating epitaxial shell growth. The resulting InP/ZnSe/ZnS QDs exhibit a narrower emission line width and better thermal stability in comparison with QDs synthesized with hydrofluoric acid. Light-emitting diodes using large-sized InP/ZnSe/ZnS QDs without replacing original ligands achieve the highest peak external quantum efficiency of 22.2%, to the best of our knowledge, along with a maximum brightness of >110 000 cd/m and a lifetime of >32 000 h at 100 cd/m. This safe approach is anticipated to be applied for a wide range of III-V QDs.
高质量的基于 InP 的量子点 (QDs) 已成为极具前景的、环境友好型的显示器用发光材料，但它们的合成通常需要使用危险的氢氟酸。在此，我们提出了一种简便的方法，可制备出具有近乎 100%光致发光量子产率的 InP/ZnSe/ZnS 核/壳/壳量子点。作为关键添加剂，无机盐 ZnF 在高温下与羧酸剧烈反应，原位生成 HF，可去除表面氧化物杂质，从而促进外延壳层生长。与使用氢氟酸合成的量子点相比，所制备的 InP/ZnSe/ZnS 量子点具有更窄的发射线宽和更好的热稳定性。使用未经替换原始配体的大尺寸 InP/ZnSe/ZnS 量子点的发光二极管实现了最高的 22.2%外量子效率峰值，据我们所知，这一效率值在 100 cd/m 下的最大亮度超过 110000 cd/m，寿命超过 32000 h。这种安全的方法有望应用于各种 III-V 量子点。
