绿色合成Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)氟化物宽带近红外荧光材料(特邀)

Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+) Fluoride Wideband Near-Infrared Fluorescence Material Synthesized by Green Method(Invited)

近红外光源对生物组织具有穿透力强、无损检测、信噪比高等特点,广泛应用于成分检测、安防监控、生物医学等领域。但是目前缺乏高效率、便携化的近红外光源,这成为了限制智能检测技术发展的关键。与传统的近红外光源相比,荧光粉转换的近红外LED光源(NIR pc-LED)具有便携、高效的特点。本研究采用工艺简单、绿色环保的水热法合成了Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)近红外宽带荧光粉,并通过控制保温温度、保温时间等参数,确定了荧光材料的最佳合成方案,研究了氟化物颗粒尺寸、形貌演化,以及Cr^(3+)掺杂浓度对Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)发光性能的影响。Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)材料能够实现630~980 nm范围宽带发射,半峰全宽(FWHM)为110 nm,峰值为766 nm,其内量子效率高达74%。结合商用蓝光LED,成功封装了近红外宽带LED光源,其在50 mA驱动电流下的近红外光输出功率是10.32 mW,光电转换效率达到5.1%。最后通过鸡胸肉下的静脉近红外成像以及夜视成像演示,验证了该近红外宽带LED光源在医疗以及食品检测等成像领域中的应用可行性。

The near-infrared light source possesses strong penetration,non-destructive testing capabilities,and a high signal-to-noise ratio for biological tissues.It finds extensive applications in component detection,security monitoring,biomedicine,national defense,and the military industry.However,the lack of highly efficient and portable near-infrared light sources has become a key obstacle to the development of intelligent detection technology.In comparison with traditional near-infrared light sources,phosphor-converted near-infrared LED light sources(NIR pc-LEDs)offer advantages such as portability and high efficiency.This study focuses on synthesizing Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)broadband phosphors through a simple and environmentally friendly hydrothermal synthesis method.By controlling factors like holding temperature and holding time,an optimal synthesis scheme for fluorescent materials is determined.The influence of fluoride particle size,morphology evolution,and Cr^(3+)doping concentration on the luminescence properties of Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)is also investigated.The synthesized Li_(3)Na_(3)Ga_(2)F_(12):Cr^(3+)material exhibits broadband emission ranging from 630 nm to 980 nm with a full width at half maximum(FWHM)of 110 nm and a peak value at 766 nm.Its internal quantum efficiency reaches an impressive 74%.Through successful packaging with commercial blue LED,a NIR wideband LED source is achieved.The output power of NIR light at 50 mA driving current is 10.32 mW,and the photoelectric conversion efficiency reaches 5.1%.Finally,the feasibility of using the NIR broadband LED light source in imaging fields such as medical and food detection is verified by NIR imaging of veins under chicken breast and night vision imaging demonstrations.