Synthesis and Photoluminescence of the Self-Activated Garnet Phosphor Triggered by Eu3+ for Blue-Red Luminescence

Abstract

The red-emitting phosphors were attracting very much interest in the fields of lighting devices. Therefore, we have prepared LiCa₃ZnV₃O₁₂:Eu³⁺ by using a simple high temperature solid-state reaction. The garnet has cubic structure that was confirmed by XRD and Rietveld refinements. The photoluminescence properties were demonstrated by emission and excitation of the samples. The excitation wavelength was 344 nm for both VO₄^3- and Eu³⁺ in the UV region while emission peaks were found at 490 nm due to VO₄^3- and at 592 nm, 611 nm and 633 nm due to Eu³⁺ but dominant peak was obtained at 611 nm in the transition from ⁵D₀ to ⁷F₁. The blue emission was confirmed by CIE chromaticity with coordinated (0.239, 0.329) and CCT was 17210 K for vanadate garnet. The surface analysis was analyzed by FE-SEM and compositional analysis was analyzed by EDX. The energy bandgap of the sample was studied by UV-VIS spectroscopy and it was found as 3.72 eV for absorbance wavelength 334 nm of the host sample. The investigation for bond length and nature of bonds in the samples were carried out with FTIR spectroscopy. For thermal stability and transitional temperature were studied by TGA/DTA analysis. The garnet phosphors that have been prepared can be applicable in the production of red and blue lighting devices, white lighting devices, optical temperature sensors, active powder in solid-state lasers, and CRTs.