宽带近红外荧光粉LaMgGa11O19:Cr^(3+),Nd^(3+)的发光特性与LED器件应用

Photoluminescence Properties and Device Performance of LaMgGa11O19:Cr^(3+),Nd^(3+)Broadband near Infrared Phosphors

具有体积小、响应快等特点的荧光转换型宽带近红外LED(NIR pc-LED)光源在食品成分分析、生物制药、癌症早期诊断、健康管理、NIR光谱技术等领域具有重要的应用价值。作为NIR pc-LED的核心组件,NIR荧光粉直接决定了这类光源的光学性能,因此开发新型高效的NIR荧光粉对于推进NIR光谱技术的普及具有重要意义。本文通过过渡族金属离子Cr^(3+)到稀土离子Nd^(3+)的能量传递设计了一种可被蓝光LED高效激发的宽带NIR荧光粉LaMgGa11O19:Cr^(3+),Nd^(3+),其发射光谱范围覆盖650~1100 nm。此外,得益于Cr^(3+)→Nd^(3+)的高效能量传递和Nd^(3+)4F3/2能级优异的发光热稳定性,该荧光粉具有优异的发光热稳定性,其发光强度在150℃时仍能维持室温的92%。最后,将LaMgGa11O19:Cr^(3+),Nd^(3+)荧光粉与蓝光LED芯片结合,所制备的NIR pc-LED原型器件,在350 mA驱动电流下,NIR输出功率高达120 mW。以上结果表明,LaMgGa11O19:Cr^(3+),Nd^(3+)荧光粉有潜力应用于NIR pc-LED器件。

Near-infrared phosphor-coverted LED(NIR pc-LED),as a compact light source with quick response,plays an important role in the applications of food analysis,bio-pharmaceutical,early diagnosis of cancer,and health management.As the core component of NIR pc-LED,NIR phosphor determine the optical properties of the device.Therefore,exploring efficient NIR phosphors is of great significance for advancing the NIR spectroscopy technology.In this paper,a high-performance LaMgGa11O19:Cr^(3+)phosphor with broadband NIR emission is presented,which covers the spectral range of 650~1100 nm under 450 nm excitation.Furthermore,the spectral range of 850~1100 nm is enhanced and supplemented by Nd^(3+)co-doping.Thanks to the efficient energy transfer from Cr^(3+)to more thermally stable Nd3+emitters,the thermal stability of the phosphors has been significantly improved.Finally,a NIR pc-LED was fabricated by combining the LaMgGa11O19:Cr^(3+),Nd^(3+)phosphors with blue LED chip,which exhibits a maximum NIR output power of 120 mW at 350 mA drive current.The results indicate that the phosphors have high promise for practical applications in NIRpc-LED.