Cationic surfactant assisted ultrasound synthesis of Dy~(3+) doped CdSiO_3 nanostructures for white LED application

摘要

In this paper we report for the first time Dy~(3+) (1-7 mol %) doped CdSiO_3 nanophosphors prepared via facile ultrasound supported sonochemical route using EGCG (epigallocatechin gallate). The final product was well characterized by PXRD, FTIR, SEM, TEM and PL. The powder X-ray diffraction (PXRD) profiles showed monoclinic phase with highly crystalline nature. The sonication time, concentration of the surfactant play vital role in tuning the morphology. The crystallite size was calculated from PXRD patterns as well as by TEM image and it was found to 20-30 nm. The Fourier transform infrared spectroscopy (FTIR) results confirmed the presence of Si-O-Si and Si-O stretching vibrations in CdSiO_3. Photoluminescence properties of Dy~(3+)(l-7 mol %) doped CdSiO_3 excited under near ultra violet wavelength (350 nm) was studied in order to investigate the possibility of its use in white light emitting diode applications. The emission spectra consists of intra 4f transitions of Dy~(3+), namely ~4F_(9/)2 → ~6H_(15/)2 (480 nm), and ~4F_(9/)2 →~6H_(13)/2 (574 nm) respectively. The 3 mol% Dy~(3+) doped phosphor showed maximum intensity. The Commission Internationale de I'Eclairage (CIE) and correlated color temperature (CCT) was evaluated. Further, the quantum efficiency and color purity results of the product showed high efficiency and it was highly useful in white light emitting diodes (wLEDs) applications.