Tunable optical properties and DFT calculations of RE3+ codoped LaBO3 phosphors

Abstract

In this study, single phase DyxLa1-xBO3, DyxCeyLa1-x-yBO3, DyxEuyLa1-x-yBO3, and TbxCeyLa1-x-yBO3 phosphors were successfully synthesized through the microwave assisted solid state method with urea. Synthesized compounds were characterized by X-Ray Diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscope, and Fluorescence spectroscopy. Thermal stabilities of the phosphors were studied with temperature dependent fluorescence measurements. In addition, density functional theory calculations were performed to investigate preferential Dy3+ ion doping sites in LaBO3 lattice. The findings of the study revealed over ten times increase in the emission intensities of phosphors were observed with Ce3+ codoping. The highest luminescence intensities were recorded for Dy0.09Ce0.05La0.86BO3 and Tb0.07Ce0.05La0.88BO3 phosphors. Furthermore, energy transfers were supported by luminescence lifetime measurements. Temperature dependent fluorescence measurements showed their thermal stabilities. According to the CIE 1931 color space, the colors of the Dy3+ only doped, Ce3+/Dy3+; Ce3+/Tb3+ and Dy3+/Eu3+ codoped phosphors were determined as off-white, white, green and yellow-orange, respectively. Intensities of the bands and the colors of the phosphors can be tuned with the choice of codopant ions or with adjustments in their concentration ratio.