Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China.
Key Laboratory of Advanced Materials of Yunnan Province, Kunming 650093, China.
ACS Appl Mater Interfaces. 2023 Aug 23;15(33):39472-39479. doi: 10.1021/acsami.3c04335. Epub 2023 Aug 8.
Transmission near-infrared (NIR) imaging technology has great potential for biomedical imaging because of its lower water absorption coefficient and highly reduced photon scattering effect in biological tissues compared to visible light. The extent of biological tissue photon scattering is inversely proportional to wavelength; therefore, in principle, imaging with long-wavelength NIR helps improve the resolution of the optical image, but deep tissue high-resolution luminescence imaging is still very challenging technically. Here, we report the discovery of a BaMgWO:Ni double perovskite phosphor that emits broadband long-wavelength NIR (1200-2000 nm) under 365 nm near-ultraviolet (UV) excitation, with a full width at half-maximum of 255 nm. The luminescence quantum efficiency of the phosphor with optimized composition reached 16.67%. The analysis of the crystal structure of BaMgWO:Ni suggests that Ni ions preferentially occupy the W site in octahedrons with a weak crystal field, which leads to a large Stokes shift. An as-prepared long-wavelength NIR pc-LED device was built by packaging an optimized phosphor with a low-power near-UV-LED chip, which was tested to generate clear imaging of venous vessels in human fingers. These unique properties of the BaMgWO:Ni double perovskite phosphor makes it a promising application in the field of imaging sources for body tissue..
传输近红外 (NIR) 成像技术在生物医学成像方面具有很大的潜力，因为与可见光相比，它在生物组织中的水吸收系数更低，光子散射效应也大大降低。生物组织中光子散射的程度与波长成反比；因此，原则上，使用长波长 NIR 进行成像有助于提高光学图像的分辨率，但深部组织的高分辨率荧光成像是非常具有挑战性的。在这里，我们报告了一种 BaMgWO:Ni 双钙钛矿荧光粉的发现，该荧光粉在 365nm 近紫外 (UV) 激发下发射宽带长波长近红外 (1200-2000nm)，半峰全宽为 255nm。优化组成的荧光粉的荧光量子效率达到了 16.67%。对 BaMgWO:Ni 晶体结构的分析表明，Ni 离子优先占据八面体中 W 位，晶体场较弱，导致较大的斯托克斯位移。通过封装优化后的荧光粉和低功率近 UV-LED 芯片构建了一个长波长近红外 pc-LED 器件，该器件被测试用于生成人体手指静脉血管的清晰成像。BaMgWO:Ni 双钙钛矿荧光粉的这些独特性质使其成为体组织成像光源领域很有前途的应用。
