Enabling Highly Efficient Neodymium Luminescence for Near‐Infrared Phosphor‐Converted Light‐Emitting Diode Applications

• Published in: Small structures 2024-09, Vol.5 (9), p.n/a
• Main Authors: Wang, Kaina, Fu, Jipeng, Dong, Hongliang, Huang, Bingyu, Liu, Jinru, Tian, Long, Feng, Jing, Yang, Chunzhen, Lou, Chenjie, Xu, Ligang, Sun, Tianyi, Luo, Huajie, Xu, Shiqing, Yin, Guowei, Zhang, Hongjie, Tang, Mingxue
• Format: Article
• Language: English
• Subjects: Biomedical materials; blue light pumping; Cerium; Density functional theory; Doping; Efficiency; Energy transfer; highly efficient luminescence; lattice distortion; Light emitting diodes; Luminescence; Near infrared radiation; near‐infrared light; Neodymium; Phosphors; Quantum efficiency; Structural analysis; Thermal stability
• ISSN: 2688-4062; 2688-4062
• DOI: 10.1002/sstr.202400092

Near‐infrared (NIR) phosphors have been widely used in biomedical applications based on their deep tissue penetration. However, the lack of blue‐pumped NIR phosphors with emission ranges beyond 1000 nm has greatly limited the development of NIR phosphor‐converted light‐emitting diodes (pc‐LEDs). Herein, a facile way to boost the luminescence efficiency and thermal stability by introducing the promoters of Ce3+ and Na+ into Nd3+‐doped SrS NIR phosphor is demonstrated, thus achieving light emitting at 850–1500 nm with a peak wavelength of ≈1070 nm. Through sensitization by the allowed 4f → 5d transition of Ce3+, the SrS: Nd3+ phosphors are excitable by using a commercial blue LED, attributing to the effective energy transfer between Nd3+ and Ce3+. Besides, the structural analysis and density functional theory calculations reveal the lattice distortion mechanism and geometry of doping ions contributed to the weakened thermal quenching effect and the increasing of internal quantum efficiency. The optimized NIR phosphor luminescence intensity remains at 91.8% of the initial intensity at 393 K, and the internal quantum efficiency increases to 42.8% from 31.7% of the sample without Na+ doping. The present exploration of Nd3+‐doped NIR phosphors will provide a reference for designing NIR pc‐LEDs with enhanced properties. Herein, a highly efficient and thermal stability near‐infrared (NIR) phosphor under blue light‐emitting diode is designed. Quantitative and mechanistic studies of the luminescence of neodymium, supported by in‐depth crystal structure analysis, will shed light on the development of novel narrowband NIR phosphors with highly desired properties beyond conventional broadband emission. The prepared narrow‐band NIR LEDs show advantages for biomedical applications.