Research on a new type of near-infrared phosphor Li2MgZrO4:Cr3+- synthesis, crystal structure, photoluminescence and thermal stability

Abstract Broadband NIR phosphors are urgently needed in NIR-LED and medical imaging. In this paper, a new type of near-infrared phosphor Li2Mg1-0.5xZr1-0.5xO4: xCr3+(0.6% ≤ x ≤ 1.6%) was synthesized by high temperature solid phase method. The optimal doping concentration of the phosphor is x = 1.0%, which exhibits broadband emission in the range of 600–1200 nm, and reaches the full width at half maximum (FWHM) of 205 nm under 462 nm blue excitation. The X-ray diffraction characterization results of the Li2Mg1-0.5xZr1-0.5xO4: xCr3+(0.6% ≤ x ≤ 1.6%) sample are refined and analyzed, and the doped sample is basically consistent with the pure phase. The sample was characterized by diffuse emission, and it was found that the sample matrix had intrinsic absorption. The thermal stability of Li2Mg0.995Zr0.995O4:1.0%Cr3+ phosphor was studied, and its relative intensity was 51.3% of room temperature at 100 °C. The results show that this new type of ultra-wide near-infrared emitting phosphor has application potential in medical imaging and PC-LED directions.