Erbium-Anchoring Surface Engineering Enables Dual-Shell Stabilized CsPbI<sub>3</sub> Quantum Dots for Efficient Pure-Red Light-Emitting Diodes.

Li, Jing; Ye, Jiajie; Zhang, Dingshuo; Hu, Xiaofeng; Lin, Shuyi; Chen, Xiuyuan; Feng, Yifeng; Yang, Chenchen et al. · Nano Lett · 2025

basic_science · Level V

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Abstract

Small-sized CsPbI<sub>3</sub> quantum dots (QDs) are promising emitters for pure-red perovskite light-emitting diodes (PeLEDs), yet their surface instability and defect formation hinder practical applications. Herein, we propose a surface doping strategy using erbium (Er<sup>3+</sup>) to enhance QD stability and suppress defects, in which Er<sup>3+</sup> ions anchor to the QD surface via strong coordination with surface iodide and oleic acid, forming a robust organic-inorganic dual-shell coordination structure that significantly inhibits undesirable degradation and Oswald ripening throughout the synthesis and purification processes. The Er-doped QDs (Er-QDs) deliver higher color purity with pure-red emission, near-unity photoluminescence quantum yield, and enhanced charge transport. Consequently, PeLEDs based on Er-QDs achieve a peak external quantum efficiency over 25% with stable emission (Commission on Illumination (CIE) 0.708, 0.292), meeting the Rec.2020 standard even under high driving voltages. This work offers a viable surface engineering strategy to stabilize perovskite QDs, enabling their application in high-performance optoelectronic devices.