Next-Generation Short-Wave Infrared LED Phosphors Based on Chromium Doped Rare Earth Sulfides.

Li, Shanshan; Zhu, Ge; Zhou, Xufeng; Wang, Chuang; Zhang, Kaicheng; Li, Zhuowei; Xu, Wen; Dong, Bin · Adv Mater · 2026

basic_science · Level V

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Abstract

External quantum efficiency (EQE) and thermal stability of phosphors are two critical parameters for next-generation short-wave infrared (SWIR) phosphor-converted light-emitting devices (pc-LEDs). However, it remains a significant challenge to develop SWIR-emitting phosphors that simultaneously exhibit high EQE and excellent thermal stability. Here, by leveraging the strong covalency, low phonon energy and structural symmetry of sulfides, we successfully realize high-performance tunable SWIR emission in sulfide phosphors NaLnS<sub>2</sub>: Cr<sup>3+</sup> (Ln = Lu, Y, Gd), peaking at 980, 1020, and 1080 nm, respectively. Notably, NaLuS<sub>2</sub>: Cr<sup>3+</sup> simultaneously achieves a record - high EQE of 61.55% along with superior thermal stability, while an EQE of 48.55% is also demonstrated at 1080 nm in NaGdS<sub>2</sub>: Cr<sup>3+</sup>. The corresponding SWIR pc-LED delivers a high SWIR output power of 169.2 mW@350 mA, significantly outperforming the commercial devices. Finally, advanced palm vein recognition and portable non-destructive detection are successfully demonstrated. This study provides new insights and an effective materials platform for developing high-performance SWIR-emitting materials toward advanced photonic applications.