OPTICAL AND STRUCTURAL STUDIES OF SAMARIUM DOPED STRONTIUM MAGNETO SILICATE PHOSPHOR SYNTHESIZED VIA SOL-GEL METHOD

Abstract

Sol-gel synthesis method was used to synthesize a series of samarium ion doped strontium magneto silicate phosphors. The structural properties of strontium magneto silicate were characterized by X-ray Diffraction (XRD) method. Fourier Transform Infrared (FT-IR) reveals the presence of functional groups in the synthesized phosphor. Diffuse reflectance spectrum is reflecting the 4.39 eV optical band gap of undoped strontium magneto silicate phosphor. Under 404 nm excitation, luminescent spectra show it have distinctive emission peaks, owing to the transition of 4G5/2 = 6HJ (J = 5/2, 7/2, 9/2, and 11/2) corresponding to the peaks centered at 564 nm, 601 nm, 646 nm and 708nm. Photoluminescence (PL) spectra shows that 2.0 mol % is the optimum concentration of Sm3+ ion to give the most intense reddish orange emission. The PL analysis shows that the exchange coupling interaction is responsible for the concentration quenching observed beyond 2.0 mol% of Sm3+ ions concentration. The chromaticity coordinates (x=0.592 and y=0.406) were calculated by photoluminescence spectra of optimized phosphor samples. The direct energy band gap was found to be 4.39 eV. All the investigation specified above signifies that the synthesized phosphor is well suited as a red emitter in lighting and display devices.