Low temperature micro Raman and laser induced upconversion and downconversion spectra of europium doped silver tungstate Ag2\u22123xEuxWO4 nanorods

Ivo M Pinatti,George R Fern,Terry G Ireland,Jack Silver,Ieda L V Rosa

doi:10.1007/s10854-016-6077-x

Abstract

All the red emitting europium-doped silver tungstate α-Ag2−3xEuxWO4 (x = 0.01–0.08 mol) phosphor reported herein crystalise as nanorods. The nanorods were structurally characterised by X-ray powder diffraction, Rietveld refinement, low temperature (20 to −190 °C) micro-Raman spectroscopy . The morphology of the nanorods reported herein was confirmed by field emission scanning electron microscopy. The optical properties were studied using low temperature (20 to −190 °C) high resolution laser excited upconversion and downconversion luminescence.

Highlights

There are several ways of producing white light from blue light emitting diodes, LEDs, the preferred way for good colour rendering involves the use of green and red emitting conversion phosphors [1]
The nanorods were structurally characterised by X-ray powder diffraction, Rietveld refinement, low temperature (20 to -190 °C) micro-Raman spectroscopy
Many tungstate lattices when acting as hosts for Eu3? activators have been shown to manifest excellent luminescent efficiency and color purity as well as having high average refractive indexes [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]. This class of tungsten oxides can be considered as ideal host lattices for dopants as they possess high thermal, chemical and physical stability and in addition they can often be synthesized at low temperatures

Summary

Introduction

There are several ways of producing white light from blue light emitting diodes, LEDs, the preferred way for good colour rendering involves the use of green and red emitting conversion phosphors [1]. Concentration in red emitting europium doped silver tungstate a-Ag2-3xEuxWO4 (x = 0.01–0.08 mol%) phosphor report to further assess its potential for use in new applications based on its’ nano-rod morphology which allows for preferred alignment, dense packing and directional emission characteristics Morphology of the nanorods was confirmed by field emission scanning electron microscopy (FESEM)

Results

Experimental

Conclusions