Precursor Type Influence on the Morphology and VUV Characteristics of GdPO_4: Tb Phosphor Particles Prepared by Spray Pyrolysis

摘要

The influence of the precursor types of phosphorus such as (NH_4)_2HPO_4, NH_4H_2PO_4, (NH_4)_3PO_4, and H_3PO_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_3PO_4, which had hollow morphology after the 3 h post-treatment anneal at 1050 deg 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)_2HPO_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)_2HPO_4 was changed from 0.5 to 1.9 mu m 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_2SiO_4 Mn phosphor particles under VUV illumination from 140 to 220 nm.