Broadband near-infrared emission in the NaInP2O7:Cr3+ phosphor for light-emitting-diode applications

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) have attracted more and more attention for the applications in spectroscopic technology, promoting the demand of searching broad-band near-infrared phosphors. In this work, Cr3+-doped NaInP2O7 phosphors with broadband NIR emission were synthesized via conventional high-temperature solid-state reaction method. The crystal, photoluminescence, and the performance of fabricated device were investigated in detail. The photoluminescence demonstrates this material exhibits an intense absorption in blue light region, matching well with the blue LED chip; while the emission spectra peaking at 870 nm covers 650–1150 nm region with a full width at half maximum (FWHM) of about 150 nm. The quantum yield (QY) and absorption efficiency was determined to be 28.2% and 49.82%, respectively, under 460 nm blue light excitation. Finally, a NIR pc-LED device was fabricated by using a commercial 455 nm blue LED combined with as-prepared NaInP2O7:Cr3+ phosphor, which has an output power of 9.08 mW and photoelectronic conversion efficiency of 2.98% under a driving current of 100 mA, indicating that the as-prepared phosphors might have a good potential for application in NIR pc-LEDs.