Huang Dayu, Ouyang Qiuyun, Xiao Hui, Wang Bo, Lian Hongzhou, Zeng Qingguang, Lin Jun
Key Laboratory of In-Fiber Integrated Optics, Ministry Education of China, and College of Physics and Opotoelectronic Engineering, Harbin Engineering University, Harbin 150001, China.
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
Dalton Trans. 2021 Jan 21;50(3):908-916. doi: 10.1039/d0dt03840g. Epub 2020 Dec 22.
The combination of a broadband near-infrared (NIR) phosphor and phosphor-converted light-emitting diodes (pc-LEDs) has proven to be an ideal choice for a high-efficiency NIR light source. Here, a garnet-type NIR CaLaHfAlO:Cr phosphor is obtained and its emission covered most of the NIR spectral range. Excited by 460 nm blue light, the maximum peak was located at 780 nm with a full width at half maximum (FWHM) of ∼141 nm and an internal quantum efficiency (IQE) of 33%. Moreover, the NIR spectra can be broadened by doping Yb into the CaLaHfAlO:Cr garnet phosphor. A super broad FWHM of 300 nm and reduced thermal quenching were acquired, originating from the energy transfer of Cr→ Yb. The energy transfer process of Cr and Yb is described by means of an energy level diagram and time-resolved spectrum. Finally, a NIR pc-LED is fabricated by combining the CaLaHfAlO:Cr,Yb phosphor with blue chips, which has a photoelectric conversion efficiency of 10%. These results demonstrate the great potential of CaLaHfAlO:Cr,Yb in super broadband NIR pc-LED applications.
宽带近红外（NIR）荧光粉与荧光粉转换发光二极管（pc-LED）的组合已被证明是高效近红外光源的理想选择。在此，获得了一种石榴石型近红外CaLaHfAlO:Cr荧光粉，其发射覆盖了大部分近红外光谱范围。在460 nm蓝光激发下，最大峰值位于780 nm，半高宽（FWHM）约为141 nm，内量子效率（IQE）为33%。此外，通过将Yb掺杂到CaLaHfAlO:Cr石榴石荧光粉中可以拓宽近红外光谱。获得了300 nm的超宽FWHM并降低了热猝灭，这源于Cr→Yb的能量转移。通过能级图和时间分辨光谱描述了Cr和Yb的能量转移过程。最后，通过将CaLaHfAlO:Cr,Yb荧光粉与蓝色芯片相结合制备了一种近红外pc-LED，其光电转换效率为10%。这些结果证明了CaLaHfAlO:Cr,Yb在超宽带近红外pc-LED应用中的巨大潜力。
