Thermally Robust Broadband Near-Infrared Luminescence in the Nagap2o7:Cr3+ Phosphor

Near-infrared (NIR) phosphor-converted light-emitting diode (pc-LED) as an emerging portable light source has applications in spectroscopy, night vision, and bioimaging, promoting the great demand to discover efficient and thermally stable broadband NIR phosphors. Herein, we report a new broadband NIR phosphor NaGaP2O7:Cr3+, which has an emission peaking at 793 nm and a full width at half-maximum (FWHM) of 115 nm. The photoluminescence quantum yield (PLQY) was determined to be 56.4%, and the emission intensity at 150 ℃ maintained 85.45% of that at room temperature, indicating an excellent efficiency and outstanding thermal stability. The thermally robust luminescence in this material stems from the high structural rigidity, wide band gap of host, and weak electron phonon coupling effect. Fabricating a NIR pc-LED device by using the asprepared NaGa0.94Cr0.06P2O7 phosphors combined with 455 nm commercial blue LED chip, an excellent NIR output power of 44.43 mW with photoelectronic conversion efficiency of 10.4% can be obtained. Thus, this work not only provide an excellent material for application in NIR spectroscopy but also highlighted some strategies for developing thermally stable broadband NIR phosphors.