Synthesis and characterization of advanced functional dysprosium doped Sr2MgSi2O7 nanopowders for white LED application

Abstract

Dy3+ doped Sr2MgSi2O7 (0–11 mol%) nanopowders were prepared by low-temperature solution combustion technique which is based on the propellant chemistry concepts. Powder X-ray diffraction study confirms the crystalline nature with a crystallite size of about 30 nm and single-phase formation with space group P4̅21m. The optical band gap and refractive indices were estimated by diffused reflectance spectroscopy. Purity of the samples and the molecular bonding strengths were identified through Fourier-transform infrared spectroscopy. Transmission electron microscopic images shows the rod-like shape with polycrystalline nature. Scanning electron microscope indicates the non-uniform and irregular shaped particles. Photoluminescence studies exhibited emission peaks at 479 nm (blue), 575 nm (yellow) and 668 nm (red) for the excitation wavelength at 348 nm attributes to white light-emission. The intensity parameters and various radiative properties were estimated using the Judd- Ofelt theory to support the optical transitions. AC Conductivity, dielectric constant studies were studied in the range of 100 Hz to 1 MHz and DC conductivity behaviors were also reported. Prepared samples showed the high dielectric constant with low dielectric loss. Hence, these silicate samples are useful for white LED components and as an electrical insulation material in nanopacking applications.