Photoluminescent Spectra of Nd3+Codoped CaAl2O4:Eu2+Blue Phosphor

Hojin Ryu,K S Bartwal

doi:10.1155/2007/23643

Abstract

Phosphor material CaAl2O4:Eu2+codoped with varying concentrations ofNd3+was prepared by solid-state reaction method. Prepared materials with 1 mol%Eu2+andNd3+(0.5 to 5 mol%) show high brightness and long persistent luminescence. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Photoluminescence excitation and emission spectra were taken to investigate the luminescence characteristics. Broadband UV excited luminescence of the CaAl2O4:Eu2+,Nd3+was observed in the blue region (λmax= 440 nm) due to transitions from4f 6 5d1to the4f 7configuration of theEu2+ion. TheNd3+ion doping in the phosphor generates deep traps which result in long afterglow phosphorescence.

Highlights

The growing demand for phosphor materials in highdefinition television screens and field-emission displays has triggered targeted studies to find new phosphors [1]
Phase and crystallinity of the synthesized compositions were investigated by powder X-ray diffraction (XRD) using Rigaku D/MAX-2200V diffractometer with Cu Kα radiation
Pure monoclinic phase diffraction peaks of parent CaAl2O4 are dominant in the XRD patterns, and are matching with the JCPDS data file

Summary

INTRODUCTION

The growing demand for phosphor materials in highdefinition television screens and field-emission displays has triggered targeted studies to find new phosphors [1]. With the development of scientific technologies on materials, several chemical synthesis techniques, such as coprecipitation [10], sol-gel [11], microwave [12], Pechini [13], and combustion [14] synthesis methods, have been applied to prepare rare earth ions activation alkaline earth aluminate and/or its phosphors. All of these methods were conducted in liquid phases so that each component can be accurately controlled and uniformly mixed. Powder XRD, SEM, and TEM measurements were performed to investigate the phase and crystallinity of the material

EXPERIMENTAL DETAILS

RESULTS AND DISCUSSION

CONCLUSIONS