Broadband La₂LiSbO₆: Cr³⁺ Phosphors with Double Luminescent Centers for NIR pc-LEDs

Abstract

The La 2 LiSbO 6 : xCr 3+ 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 3+ ions are discussed in detail. The optimized doping concentration of Cr 3+ is determined to be 0.01. Under 517 nm excitation, the La 2 LiSbO 6 : 0.01Cr 3+ 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 La 2 LiSbO 6 : 0.01Cr 3+ phosphor at 373 K is about 63.7% of that at room temperature, exhibiting good thermal stability. Aiming to fabricate a nearinfrared phosphor-converted light-emitting diode device, the La 2 LiSbO 6 : 0.01Cr 3+ 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 La 2 LiSbO 6 : 0.01Cr 3+ phosphor is promising for night vision.

Blue light-excited broadband NIR-II-emitting Li2ZnSn3O8:Cr3+,Ni2+ phosphor for multifunctional optical applications

“…Moreover, no characteristic absorption band of Cr 4+ around 1000 nm was observed in the LZSO:0.03Cr 3+ sample, indicating that the emission center is Cr 3+ ions rather than Cr 4+ . 37 Meanwhile, the PL spectrum of LZSO:0.03Cr 3+ and the PLE spectrum of LZSO:0.03Ni 2+ show a significant overlap, as shown in Fig. S3, † demonstrating that the ET between Cr 3+ and Ni 2+ is possible.…”

Broadband Near-Infrared Sr3Al9.8SiO20:0.2Cr Phosphor Realized by Crystallographic Site Engineering

“…Broadband near-infrared (NIR) light attracts immense attention due to its multifunctional potential applications in nondestructive testing, medical imaging, night vision, agricultural production, etc. − Although traditional NIR light sources such as halogen tungsten lamps and incandescent bulbs can emit continuous wavelengths of light from visible to NIR regions, the drawbacks, such as large size, high working temperature, and low luminous efficiency, hinder their further applications in various fields. − In recent decades, phosphor-converted light-emitting diode (pc-LED) technology has triggered profound changes in the field of display and lighting, especially the superiorities in high efficiency, compactness, and low cost brought about by the rapid development of pc-LED technology, making NIR pc-LEDs more attractive than traditional NIR light sources. − Therefore, the NIR phosphors that can be pumped by commercial LED chips with broadband emission are prerequisites of the NIR pc-LED development. − …”