Spectroscopic Properties of Blue Light-Emitting Li2SiO3:xGd3+ Phosphors for Solid State Lighting Applications

Abstract

A series of blue light-emitting Li₂SiO₃:xGd³⁺ phosphors were prepared via a solid-state reaction method at 950℃ for 3 h in an air atmosphere. According to the powder X-ray diffractometer (PXRD) and Rietveld refinment analysis, the crystalline structure of the Li₂SiO₃:xGd³⁺ phosphors matrix did not significantly change. The optical band gaps E_g of the sintered Li₂SiO₃:0.03Gd³⁺ material has been calculated by 5.62 eV by the Tauc plot. Photoluminescence (PL) investigation of Li₂SiO₃:xGd³⁺ phosphors displayed an intense blue emission peak of Gd³⁺ ions ⁸S_7/2 → ⁶I_7/2 transition, under near utra-violet (NUV) excitation of 276 nm. After the concentration of Gd³⁺ ions in the Li₂SiO₃ host reached 0.03 mol, the concentration quenching occurred, indicating that it had reached an optimal concentration. Under the UV excitation (276 nm); theLi₂SiO₃: 0.03Gd³⁺ materials exhibit good temperature stability. The emission intensity, Commission Internationale de lEclairage (CIE) chromaticity coordinates, correlated color temperature (CCT), color purity, and quantum efficiency of Li₂SiO₃:0.03Gd³⁺ phosphor were comprehensively enhanced by Gd³⁺ doping. The blue region's CIE coordinate value confirms that Li₂SiO₃:Gd³⁺ can be utilized as a component in solid-state display applications and artificial blue light-emitting diode (LED) generation.