Journal of Materials Research and Technology (Nov 2020)
Effects of synthesis temperature and Eu2O3 concentration on the crystalline phases and photoluminescence properties of SrAl2O4 phosphors
Abstract
Phosphors with the compositions of x% Eu2O3-doped SrAl2O4 (x = 0.25, 0.5, 0.75, and 1.0, in mole ratio) were synthesized in air using solid state reaction method. From the SEM observations, we had found that the nano-cotton-filament-structured crystals were formed on the particle surfaces of all synthesized x% Eu2O3-doped SrAl2O4 powders, and their volume decreased with raising synthesis temperature. XRD patterns, TEM observations, and EDS analyses were used to analyze and confirm the compositions of the formed nano-cotton-filament-structured crystals, and the reaction sequences of Eu2O3-doped SrAl2O4 were well presented and proven in this study. When 260–265 nm were used as excitation wavelength, all the synthesized x% Eu2O3-doped SrAl2O4 phosphors would show photoluminescence emission intensity at three emission peaks with wavelengths of 590–592, 610–612, and 658 nm, which are respective corresponding to 5D0 → 7F1, 5D0 → 7F2, and 5D0 → 7F3 transitions of Eu3+ ions. The emission intensities of those characteristic peaks were apparently affected by the Eu2O3 concentration and synthesis temperature, and the concentration quench effect was also observed. The dominated emission light of all x% Eu2O3-doped SrAl2O4 phosphors was the transition of 5D0 → 7F1 (590–592 nm) peak, which was different from before research, and we would well discuss and explain the reason to cause this result.
