上海大学张建华团队制备了用于高效稳定纯蓝色LED的均匀ZnSeTeS量子点。相关论文于2025年3月5日发表在《自然》杂志上。

无重金属蓝色量子点（QD）发光二极管（QLED）的电致发光性能远低于最先进的镉基发光二极管。环保的ZnSeTe量子点是镉基蓝色量子点的理想替代品，但面临着颜色杂质和由主导成分不均匀性的聚集碲（Te_n≥2）引起的稳定性较差的问题。

研究组开发了一种使用同族硫与亚磷酸三苯酯（TPP-S）配位的等电子控制策略，以构建具有纯蓝色发射和近单位光致发光量子产率的均匀ZnSeTeS量子点。低供电子能力的TPP促进了阴离子前体之间的反应平衡，有利于组成均匀的量子点的生长。具有高电负性的受体样S通过干扰周围的载流子削弱了碲原子的空穴局域化，从而抑制了Te_n≥2个等电子中心的形成。此外，同源S增加了量子点的构型熵，消除了层错和氧缺陷，从而提高了结构稳定性并降低了非辐射载流子密度。

因此，基于核壳ZnSeTeS/ZnSe/ZnS量子点在460 nm下发射的纯蓝色QLED显示出24.7%的高外部量子效率、17 nm的窄线宽和在100 cd cm⁻²下接近30000小时的长工作半衰期（T₅₀），可与最先进的镉基蓝色QLED相媲美。

附：英文原文

Title: Homogeneous ZnSeTeS quantum dots for efficient and stable pure-blue LEDs

Author: Wu, Qianqian, Cao, Fan, Yu, Wenke, Wang, Sheng, Hou, Wenjun, Lu, Zizhe, Cao, Weiran, Zhang, Jiaqi, Zhang, Xiaoyu, Yang, Yingguo, Jia, Guohua, Zhang, Jianhua, Yang, Xuyong

Issue&Volume: 2025-03-05

Abstract: The electroluminescence performance of heavy-metal-free blue quantum dot (QD) light-emitting diodes (QLEDs) is much lower than that of state-of-the-art cadmium-based counterparts. Ecofriendly ZnSeTe QDs are an ideal alternative to cadmium-based blue QDs1,2, but face issues with colour impurity and inferior stability caused by the aggregated tellurium (Ten≥2) that dominates compositional inhomogeneity3,4. Here we developed an isoelectronic control strategy using congeneric sulfur coordinated with triphenyl phosphite (TPP-S) to construct homogeneous ZnSeTeS QDs with pure-blue emissions and near-unity photoluminescence quantum yield. TPP with low electron-donating capability promotes the reactivity balance among anionic precursors, favouring the growth of QDs with uniform composition. The acceptor-like S with high electronegativity weakens the hole localization of the Te atoms by interfering with their surrounding carriers, thereby suppressing the formation of Ten≥2 isoelectronic centres. Furthermore, the congeneric S increases the configurational entropy of the QDs and eliminates the stacking faults and oxygen defects, leading to improved structural stability and reduced non-radiative carrier density. Consequently, the resulting pure-blue QLEDs based on core–shell ZnSeTeS/ZnSe/ZnS QDs emitting at 460nm show a high external quantum efficiency of 24.7%, a narrow linewidth of 17nm, and long operational half-lifetime (T50) close to 30,000hours at 100cdcm2, rivalling state-of-the-art cadmium-based blue QLEDs.

DOI: 10.1038/s41586-025-08645-4

Source: https://www.nature.com/articles/s41586-025-08645-4