Red Emission of Ca[sub 6]Gd[sub 1.97]Eu[sub 0.03]Na[sub 2](PO[sub 4])[sub 6]F[sub 2] with Suitable Chromaticity Coordinates under VUV Excitation

Abstract

Europium-activated apatite phosphors Ca 6 Gd 2-x Eu x Na 2 (PO 4 ) 6 F 2 (x = 0.01, 0.03, 0.05, 0.07, 0.09, and 0.10) were prepared by a conventional solid-state reaction method. The vacuum ultraviolet (VUV)-vis spectroscopic properties were investigated. The luminescence of optimum phosphor Ca 6 Gd 1.97 Eu 0.03 Na 2 (PO 4 ) 6 F 2 (CGPF-Eu) is compared with that of commercially available red phosphor (Y,Gd)BO 3 :Eu (YGB-Eu). The result shows that the luminescence intensity of CGPF-Eu is around 70.6% of that of YGB-Eu upon 172 nm excitation. The values of chromaticity coordinates and the luminescence photographs demonstrate that CGPF-Eu has a more suitable red emission than YGB-Eu.