ScholarWorks@동국대학교

초록

The development of triple oxide semiconductor nanostructures (NS) with special optical window is critical for the optoelectronics and the luminescent industry. The present article describes the synthesis of Sm-x:Gd(1-x)@SrO (x = 0.4, 0.6, 0.8) NS by simple Coprecipitation method. The NS were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), SEM-EDS (energy dispersive spectra), Fourier transform infrared (FT-IR), UV-visible, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller analytical methods. The results of the powdered XRD pattern revealed the formation of mixed-phase of hexagonal crystal structure, with grain size between 62 and 78 nm. Redshift in optical absorption spectra for the Sm3+ doped Gd(1-x) SrO NS appeared when compared to Gd(1-x) SrO NS. Photoluminescence (PL) spectroscopy demonstrated broad deep defect levels in Sm-x: Gd(1-x) SrO NS when compared to Gd(1-x) SrO NS. PL studies of Gd-0.6, SrO exhibited three emission peaks detected at 373.6 nm, 382.1 nm, and 392.7 nm when excited at 325 nm. PL studies of Sm-x: Gd(1-x) SrO NS (x = 0.8) showed four emission peaks appeared at 415 nm (violet), 472 nm (blue), 532.1 nm (green) and 569.6 nm (yellow) due to f-f transition of Sm3+ in 4f(5) configuration. Higher values of dielectric constant (3.86 x 10(4)), dielectric permittivity (10(3)-10(5)) resulted for the Sm-x:Gd(1-x)@SrO (x = 0.8) NS with negligibly small dielectric loss (< 0.03) when compared to Gd-0.6 SrO NS. The synthesised materials demonstrated excellent luminescence properties with good dielectric properties therefore these materials could be good candidates to be used as high-luminescent devices. (GRAPHICS)

키워드