Broadband La 2 LiSbO 6 : Cr 3+ Phosphors with Double Luminescent Centers for NIR pc-LEDs.

The LaLiSbO: Cr phosphors were synthesized by means of a high-temperature solid-phase method. Based on the differences in ionic radius, valence state, and formation energy, the substitution sites of Cr ions are discussed in detail. The optimized doping concentration of Cr is determined to be 0.01. Under 517 nm excitation, the LaLiSbO: 0.01Cr phosphor presents a wide emission band (from 700 to 1350 nm) with a peak centered at 952 nm. Additionally, its corresponding full width at half-maximum is 155 nm, and the internal quantum efficiency reaches 62.4%. Meanwhile, the emission intensity of the LaLiSbO: 0.01Cr phosphor at 373 K is about 63.7% of that at room temperature, exhibiting good thermal stability. Aiming to fabricate a near-infrared phosphor-converted light-emitting diode device, the LaLiSbO: 0.01Cr phosphor is mixed with epoxy adhesive and cured on a green light-emitting diode chip. Under the irradiation of the fabricated light-emitting diode device, fruits and writing in the dark environment can be captured by a near-infrared camera. Hence, the LaLiSbO: 0.01Cr phosphor is promising for night vision.