8-12 July 2013
Photoluminescence properties of rare-earths and manganese doped strontium aluminate phosphors prepared by combustion method.
Presented by Mr. Manaka MMAKGABO on 9 Jul 2013 from 17:40 to 18:40
Type: Poster Presentation
Track: Track A - Division for Condensed Matter Physics and Materials
Alkaline earth aluminate hosts have attracted a lot interest, due to their stable crystal structure, high physical and chemical stability. Strontium Aluminate (SrAl<sub>2</sub>O<sub>4</sub>) host material have been proven to be efficient with a wide band gap, which offers the possibility of generating broad band emission. In this study SrAl<sub>2</sub>O<sub>4</sub> doped with Eu<sup>2+</sup>, Dy<sup>3+</sup> and Mn<sup>2+</sup> phosphor powders were prepared by combustion method at 600°C. The X-ray diffraction (XRD) patterns of the samples were performed using a Bruker AXS D8 advanced automatic diffractometer with Cu-Kα radiation (λ = 1.5418 A), operating at 40 kV and 30 mA. The photoluminescence (PL) and photoluminescence excitation (PLE) spectra were measured at room temperature using a Spex Fluorolog-3 spectrofluorometer (Instruments S.A., N.J., U.S.A) equipped with a 450 W Xe light source and double excitation monochromators. The PL emission spectra of SrAl<sub>2</sub>O<sub>4</sub> doped with Eu<sup>2+</sup> and Dy<sup>3+</sup> shows the influence of excitation wavelength on the emission spectra of the sample. The broad and sharp emission bands observed are typical transitions of Eu<sup>2+</sup> and Eu<sup>3+</sup> respectively. The broad emission bands from these spectra are attributed to the typical transitions from the lowest <sup>2</sup>D level of the excited 4f<sup>6</sup>5d<sup>1</sup> configuration to the ground <sup>8</sup>S<sub>7/2</sub> level of the 4f<sup>7</sup> configuration of Eu<sup>2+</sup> ion. The sharp emission lines can be attributed to the (<sup>5</sup>D<sub>0</sub> - <sup>7</sup>F<sub>1-5</sub>) electronic transition of Eu<sup>3+</sup> ions present in the host matrix. The particle morphologies of the powders were investigated using Zeiss High resolution SEM.
Dr Mothudi, email@example.com, UNISA