Luminescence Characteristics of Eu and Tb Doped YGdBO3 Phosphor

Abstract

Abstract The main aim of this paper is to synthesize rare earth doped phosphors for display applications in Compact fluorescent Lamps (CFLs) and test the utility of these phosphors in accidental radiation dosimetry. The present paper reports the Photoluminescence (PL) and Thermoluminescence (TL) characteristics YGdBO3 doped with Eu and Tb phosphors. The method of preparation followed is a standard solid state reaction (SSR). The PL observed with excitation at 254 nm for the YGdBO3 doped with Eu generates emission at 367, 454,595, 611 and 628 nm. The intensity of peak at 366 nm is relatively less as compared to 594, 613 and 629nm peaks. Photoluminescence spectra of YGdBO3: Tb3+(0.5%) being excited with 254 nm generates an emission at 367, 470,489, 497 and 545 nm. The PL emission at 545 nm is very sharp and followed by a hump at 554 nm. The peak observed at 367 in both the specimens are normally due to crystal field. Thermoluminescence studies of beta irradiated YGdBO3: Eu and Tb3 did show good well defined high intensity isolated TL peak around 200oC. The calculated trap depth is 0.4ev. The TL dosimetry (TLD) studies are interesting. It is proposed the YGdBO3: Tb3+ can be used as lamp as well TLD phosphor in the case of accidental radiation monitoring. It is found the YGdBO3:Tb3+ phosphors can act as phosphor in compact fluorescent lamps as well as a radiation detector in case of accidental nuclear fallout like recent one in Japan, a two in one concept.