Latest Nature paper of Shanghai University: 24.7%! 30,000-hour half-life! Homogeneous ZnSeTeS quantum dots can be used for efficient and stable pure blue LEDs

The team of Zhang Jianhua & Yang Xuyong from Shanghai University and Zhang Jiaqi from Jilin University published a research paper titled "Homogeneous ZnSeTeS quantum dots for efficient and stable pure-blue LEDs" in the journal Nature. Wu Qianqian & Cao Fan are the co-first authors, and Zhang Jianhua & Yang Xuyong & Zhang Jiaqi are the co-corresponding authors.

Key Highlights: This paper proposes a strategy to suppress the heterogeneity of Te-containing quantum dots through isoelectronic manipulation. By introducing triphenyl phosphite (TPP-S) with appropriate reactivity, a homogenized quaternary alloy of blue ZnSeTeS quantum dots was successfully prepared. A blue QLED device based on this quaternary quantum dot exhibits an external quantum efficiency of 24.7%, a full width at half maximum of 17 nm, and a T50 lifetime of nearly 30,000 hours.

The electroluminescent performance of heavy-metal-free blue quantum dot (QD) light-emitting diodes (QLEDs) is significantly inferior to that of state-of-the-art cadmium-based QDs. Environmentally friendly ZnSeTeS QDs are promising alternatives to cadmium-based blue QDs, but they suffer from color impurities and poor stability due to aggregated tellurium (Ten ≥ 2), a primary contributor to compositional heterogeneity.

In light of this, the research team led by Zhang Jianhua, Yang Xuyong, and Zhang Jiaqi from Shanghai University and Jilin University developed an isoelectronic control strategy using a homologous sulfur coordinated with triphenylphosphite (TPP-S) to construct homogeneous ZnSeTeS QDs with pure blue emission and near-100% photoluminescence quantum yield. The low electron-donating capacity of TPP promotes the reactivity balance between anionic precursors, favoring the growth of QDs with uniform composition. The highly electronegative acceptor sulfur weakens the hole localization of the Te atom by interfering with surrounding carriers, thereby suppressing the formation of Ten ≥ 2 isoelectronic centers. Furthermore, homologous sulfur increases the quantum dot's configurational entropy and eliminates stacking faults and oxygen defects, thereby improving structural stability and reducing non-radiative carrier density. Consequently, a pure blue QLED based on core-shell ZnSeTeS/ZnSe/ZnS quantum dots emits at 460 nm, exhibiting a high external quantum efficiency of 24.7%, a narrow linewidth of 17 nm, and a long operating half-life (T50) of nearly 30,000 hours at 100 cd cm⁻², comparable to state-of-the-art cadmium-based blue QLEDs.

This research breaks new records for the luminous efficiency and stability of heavy metal-free pure blue QLEDs, which will advance the environmentally friendly development of QLED display technology.

Source：https://doi.org/10.1038/s41586-025-08645-4