Precursor Type Influence on the Morphology and VUV Characteristics of GdPO[sub 4]:Tb Phosphor Particles Prepared by Spray Pyrolysis

Abstract

The influence of the precursor types of phosphorus such as (NH 4 ) 2 HPO 4 , NH 4 H 2 PO 4 , (NH 4 ) 3 PO 4 , and H 3 PO 4 on the morphology and vacuum ultraviolet (VUV) characteristics of GdPO 4 :Tb phosphor particles prepared by spray pyrolysis was investigated. All prepared GdPO 4 :Tb phosphor particles had spherical shape and dense structure except for the sample prepared with H 3 PO 4 , which had hollow morphology after the 3 h post-treatment anneal at 1050°C. The phosphorus type also affected the photoluminescence (PL) intensity of GdPO 4 :Tb phosphor particles. The highest PL intensity under VUV excitation was obtained with (NH 4 ) 2 HPO 4 used as the precursor. For optimizing the PL intensity of spherical particles, the average particle size of GdPO 4 :Tb phosphor particles prepared using (NH 4 ) 2 HPO 4 was changed from 0.5 to 1.9 μm and the effect on PL intensity was investigated. The optimized GdPO 4 :Tb particles have a good excitation spectrum comparable to that of the commercial Zn 2 SiO 4 :Mn phosphor particles under VUV illumination from 140 to 220 nm.