Visible quantum cutting in Tb~(3+) doped BaGdF~5 phosphor for plasma display panel

摘要

Visible quantum cutting (QC) via down-con-version and enhancement in photoluminescence properties has been observed in terbium (Tb~(3+)) doped BaGdF_5 phosphor. This phosphor was synthesized by varying molar concentration of Tb~(3+) ions via co-precipitation method. The prepared phosphor was characterized through X-ray diffraction technique. The photoluminescence spectra of BaGdF_5:Tb~(3+) phosphor measured under vacuum ultraviolet or UV excitation. The QC process was observed in prepared phosphor due to cross relaxation and direct energy transfer between Tb~(3+) and Tb~(3+) or Tb~(3+) and Gd~(3+) ions depending on the excitation wavelength. The maximum quantum efficiencies were found to be 162, 174 and 177 %, under the excitation of 172, 187 and 240 nm respectively. The green emission of 544 nm was observed at excitation of 172 and 187 nm. Hence this phosphor may be prime candidate for application in plasma display panels and mercury free fluorescent lamps.