Structural and optical properties of Sm3+doped Sr2SiO4 phosphor prepared from coal gasification slag for the LED application

In this paper, Sr2SiO4 phosphors with different Sm3+ concentrations and Sr2SiO4:0.006Sm3+ phosphors obtained from the coal gasification slag as raw materials have been synthesized by the high-temperature solid-phase method. The influence of Sm3+ ions and the purity of SiO2 on the structural and optical attributes of Sr2SiO4 have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) spectrum, photoluminescence (PL) spectra and fluorescence lifetime analysis. XRD results showed that the doping ions have entered into the host lattice, and SEM shown the crystallite sizes have been found to vary from 1 to 3 mu m. PL spectra displayed that the emission intensity of the samples increased with the increase in concentrations of Sm3+ ions. At the optimum doping concentration, the luminous intensity and fluorescence lifetime of the sample prepared by the purified silica is much higher than that of the phosphor prepared by the chemical product silica, which is close to that of the pure chemical reagent. Finally, we explored the application of fluorescent powder in pc-WLED devices. Notably, the devices exhibited excellent luminous performance at 20 mA current. The results demonstrate that coal gasification slag (CGS) product can be used to synthesize brilliant materials with potential uses for the pc-WLED technology.