posted on 2022-01-19, 19:35authored byGaochao Liu, Maxim S. Molokeev, Zhiguo Xia
Broadband near-infrared (NIR) light
sources based on phosphor-converted
light-emitting diodes (pc-LEDs) are desirable for biochemical analysis
and medical diagnosis applications; however, the development of target
NIR phosphor is still a challenge. Herein, broadband NIR phosphors,
Cr3+-activated CaSc1–xAl1+xSiO6 (λem = 950 nm), are designed and optimized by chemical substitution toward
enhanced quantum efficiency and thermal stability. Structural and
spectral analyses along with density functional theory calculations
reveal that Sc3+/Al3+ substitution contributes
to enhancing the structural rigidity and the local symmetry of the
[Sc/AlO6] octahedron so that the nonradiative relaxation
of Cr3+ emission centers is suppressed significantly. The
as-fabricated phosphor-in-glass-based NIR LED light source demonstrates
great potential in the detection of alcohol concentration. This study
provides a local structure design principle for exploring NIR phosphors
with enhanced thermal stability and will also stimulate further studies
on material discovery and quantitative analysis of NIR spectroscopy.