Unlocking non-characteristic near-infrared emission of rare earth ions for photosynthetic bacteria cultivation and vein imaging applications

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2024-09, Vol.12 (37), p.157-1581
• Main Authors: Lin, He, Fang, Shuangqiang, Lang, Tianchun, Yu, Jiali, Cheng, Haoliang, Ou, Jiaqi, Ye, Zhijie, Xu, Renjie, Shui, Xiulan, Qu, Haolin, Wang, Le
• Format: Article
• Language: English
• Subjects: Bacteria; Electron paramagnetic resonance; Holmium; Infrared imaging; Light emitting diodes; Near infrared radiation; Nondestructive testing; Optoelectronics; Phosphors; Photosynthesis; Quantum efficiency; Shielding; Synergistic effect; Thulium; Trivalent chromium
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d4tc02130d

Near-infrared (NIR) luminescent materials exhibit unique photophysical properties that make them crucial components in photobiological, photonic and optoelectronic applications. Nonetheless, almost all rare earth ions are difficult to be efficiently excited by blue light for NIR emission, mainly due to the inherent electron shielding effect of 5s 2 5p 6 orbitals. Here, an amazing enhancement of the Tm 3+ 3 H 4 → 3 H 6 transition (800 nm) was achieved in the SrGa 12 O 19 host upon 450 nm excitation. Compared with the Tm 3+ single-doped sample, the internal quantum efficiency (IQE) in the 700-900 nm range was significantly improved from less than 1% to 74%, and the external quantum efficiency (EQE) was enhanced from nearly 0 to 33%, benefitting from the synergistic effect of Cr 3+ contribution and electron shielding effect breaker of In 3+ . XRD structure refinement, time-resolved fluorescence spectroscopy and electron paramagnetic resonance were used to determine the effect of Cr 3+ and In 3+ doping. Furthermore, the universality of this strategy has also been verified with other rare earth ions (Ho 3+ , Nd 3+ , and Yb 3+ ). Finally, a NIR phosphor-converted LED (pc-LED) is fabricated, exhibiting a satisfactory output power of 141 mW@500 mA and demonstrating the potential for photosynthetic bacteria culture, venous imaging and non-destructive testing. This work opens a window for blue light-pumped NIR emission of rare earth ions. Near-infrared (NIR) luminescent materials exhibit unique photophysical properties that make them crucial components in photobiological, photonic and optoelectronic applications.