A near-infrared emitting of Cr3+-doped Li2 ZnSn2 O6 materials prepared by a solid-state reaction method

Abstract

In this study, the broadband NIR emitting Cr³⁺-doped Li₂ZnSn₂ O₆ phosphors (Li₂ZnSn₂ O₆:Cr³⁺) were fabricated by using the solid-state reaction method. X-ray diffraction analysis (XRD) analysis results showed that the single[1]phase of Li₂ZnSn₂ O₆:Cr³⁺ materials were formed at 950 and 1050^o
C. At higher temperatures of 1050^oC, two phases of Li₂ZnSn₂ O₆-SnO₂ were created. Field emission scanning electron microscopy (FESEM) images indicated that Li₂ZnSn₂ O₆:Cr³⁺ materials annealed at 950^oC were granular with particle size in the range of 100-300 nm and reached the maximum particle size of ∼1 μm at 1200^oC. The results of photoluminescence (PLE) excitation spectra and photoluminescence (PL) spectra showed that the Li₂ZnSn₂ O₆:Cr³⁺ materials which could be well excited in the wavelength range of 260-500 nm, strongly emitted in the broadband near-infrared light region peaking at 797 nm. Under experimental conditions, the highest PL intensity was observed in the Li₂ZnSn₂ O₆:0.7%Cr3+ sample annealed at 1050°C for 5 hours in the air. The obtained results indicated that the synthesised Li₂ZnSn₂ O₆:Cr³⁺ materials have great potential for NIR LED applications.