| Reflection Modelling and enhanced luminescence properties of phosphors coated by nano-layers of silica |
| Paper ID : 1059-UFGNSM-FULL (R2) |
| Authors: |
|
Seyed Mahdi Rafiaei * Golpayegan University of Technology, Golpayegan 87717-65651, Iran |
| Abstract: |
| In this investigation firstly Eu3+ doped YVO4 phosphor material was synthesized using a simple solid state approach at 1100 °C. Then silica layers with the thickness of 20-50 nm were coated on the surface of phosphors via a modified sol-gel method by the source of Tetraethyl orthosilicate (TEOS) at relatively low temperatures. The crystal structures of synthesized coated and bare materials were characterized by an X-ray diffractometer (XRD) with CuKα radiation (λ = 1.54 Å). The particle size and morphology were studied by using a field emission scanning electron microscope (FESEM) and a high resolution transmission electron microscope (HRTEM), separately. The optical properties of fabricated phosphors was characterized by a PL analyzer equipment too. It was found that covering the surface of phosphors by silica resulted in increase of emission intensities of Eu3+ doped YVO4 red phosphors (with the approximate wavelength of 618 nm). In order to understand the mechanism of enhancing luminescence properties, Euler equation was used successfully. By employing this powerful model, it was shown that silica coating layers reduces the reflection of excitation light and reinforces the emission behavior. Meanwhile, it was observed that coating relatively thicker layers of silica results in decrease of efficiency and suppression of optical properties. |
| Keywords: |
| Solid state, Sol-gel, Silica, Coating, photoluminescence |
| Status : Paper Accepted (Oral Presentation) |
