Efficient near-infrared luminescence in phosphate Na2AlTi(PO4)3:Cr3+ for light-emitting-diodes applications

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) have an extensive range of applications within multiple fields, such as bioimaging, night vision and non-destructive examination. Therefore, developing broadband, low-cost, and efficient NIR phosphors capable of satisfying the demands of the above applications is desired. In this work, a series of inexpensive phosphate Na 2 AlTi(PO 4 ) 3 :Cr 3+ phosphors were developed. This material shows a broadband NIR emission covering 700-1200 nm with emission peak located at 830 nm and a full width at half maximum (FWHM) of 152 nm under 470 nm excitation. Moreover, the photoluminescence quantum yield (PLQY) can be optimized to 79.1%, suggesting a high efficiency among octahedral Al 3+ -containing NIR materials. Finally, a prototype NIR pc-LED device was fabricated via directly coating the InGaN blue LED chip with the optimized Na 2 AlTi(PO 4 ) 3 :Cr 3+ phosphor. The NIR output power of the device was determined to be 17.24 mW at 100 mA driving current, and the corresponding NIR photoelectric conversion efficiency was 7.51%, indicating the excellent output performance, and good potential in practical applications.