Broadband near-infrared (NIR) phosphors converted light-emitting diodes (pc-LEDs) have attracted tremendous attention for their great potential in NIR spectroscopy applications. Herein, we report on the photoluminescence (PL) properties of Cr 3+ -doped Sc(PO 3 ) 3 , which exhibits a broadband NIR emission centered at 900 nm with a full width at half-maximum (FWHM) of 161 nm upon excitation at 480 nm. In terms of the examination of spectroscopic parameters, we find that Cr 3+ ions occupy a weak crystal field site (Dq/B = 1.94) in the Sc(PO 3 ) 3 host with a stronger electron-phonon coupling (Huang-Rhys factor, S = 5.5), which results in a serious thermal quenching and a low internal quantum efficiency (IQE). Thermal stability and IQE of phosphors can be substantially enhanced by the introduction of Yb 3+ ions. In the light of the analysis of excited-state dynamics, we demonstrate that the enhancement mechanism is ascribed to the efficient Cr 3+ →Yb 3+ energy transfer from the thermal sensitive Cr 3+ centers to the thermal stable Yb 3+ emitters. An NIR pc-LED device has been finally fabricated by the combination of a blue-emitting chip and a Cr 3+ /Yb 3+ codoped Sc(PO 3 ) 3 phosphor whose potential application for broadband NIR pc-LEDs is also discussed.
K E Y W O R D Sbroadband near-infrared, Cr 3+ , energy transfer, phosphor-converted LED, Sc(PO 3 ) 3