Minzhong Li,Yahong Jin,Lifang Yuan,Bo Wang,Haoyi Wu,Yihua Hu,Feng Wang
The advent of near-infrared (NIR) afterglow in Cr3+-doped materials has stimulated considerable interest in technological applications owing to the sustainable emission of light with good penetrability. However, the development of Cr3+-free NIR afterglow phosphors with high efficiency, low cost, and precise spectral tunability is still an open question. Herein, we report a novel Fe3+-activated NIR long afterglow phosphor composed of Mg2SnO4 (MSO), in which Fe3+ ions occupy the tetrahedral [Mg–O4] and octahedral [Sn/Mg–O6] sites, giving rise to a broadband NIR emission spanning 720–789 nm. On account of energy-level alignment, the electrons released from the traps show a preferential return to the excited energy level of Fe3+ in tetrahedral sites through tunneling, leading to a single-peak NIR afterglow centered at 789 nm with a full-width at half-maximum (fwhm) of 140 nm. The high-efficiency NIR afterglow, showing a record persistent time lasting over 31 h among Fe3+-based phosphors, is demonstrated as a self-sustainable light source for night vision applications. This work not only provides a novel Fe3+-doped high-efficiency NIR afterglow phosphor for technological applications but also establishes practical guidance for rational tuning of afterglow emissions.
Bo-Mei Liu,Xiao-Xuan Guo,Lin Huang,Rong-Fu Zhou,Rui Zou,Chong-Geng Ma,Jing Wang
Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) have sparked tremendous interest in NIR spectroscopy. However, conventional NIR pc-LEDs with a narrow full-width at half-maximum (FWHM) and single-emission block the detection scope and detection accuracy for NIR spectroscopy analysis. Herein, a multicenter strategy is developed for the preparation of blue-light-excitable Mg 2 SnO 4 :Cr 3+ ,Ni 2+ phosphors with NIR dual-emission (λ em = 830/1480 nm, total FWHM = 532 nm). Benefiting from the unique NIR dual-emission, a ratiometric measurement system with a self-calibration function is established for highly precise and nondestructive detection. For the first time, a good linear relationship with a detection limit of 0.22 wt.% is achieved for quantitative, non-invasive detection of water/ethanol mixtures in the field of NIR spectroscopy applications. Additionally, a super-broadband pc-LED with a NIR output power of 16.1mW@300 mA is fabricated, demonstrating its applications in high-penetration imaging and anticounterfeiting. These results provide an approach to achieving NIR dual-emission phosphor, thereby opening a new avenue for exploring ratiometric NIR spectroscopy techniques.
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