Luminescent Properties of Eu[sup 3+] and Tb[sup 3+] Activated Zn[sub 3]Ta[sub 2]O[sub 8]

Abstract

This paper reports a systematic investigation on photoluminescent (PL) properties of Eu3+Eu3+ and Tb3+Tb3+ -activated Zn3Ta2O8.Zn3Ta2O8. The excitation spectrum of Zn3Ta2O8:Eu3+Zn3Ta2O8:Eu3+ consists of the strong CTS absorption and week f-f transitions of Eu3+,Eu3+, while the excitation spectrum of Zn3Ta2O8:Tb3+Zn3Ta2O8:Tb3+ is composed of the strong d-f transition and weak f-f transitions of Tb3+.Tb3+. The charge transfer state (CTS) band of Eu3+Eu3+ and the d-f peak of Tb3+Tb3+ slightly shift to lower energy with increase of dopant contents. Zn3Ta2O8:Eu3+Zn3Ta2O8:Eu3+ exhibits red emission peaks around 610-620 nm, which is related to the transitions of 5D0→7F2.5D0→7F2. The luminescence of Zn3Ta2O8:Tb3+Zn3Ta2O8:Tb3+ is dominated by green emission peaks at 546 nm, which can be attributed to the transition of 5D4→ 7F5.5D4→ 7F5. For Eu3+­Tb3+Eu3+­Tb3+ codoped Zn3Ta2O8,Zn3Ta2O8, energy transfer process takes place and the resonant mechanism is proposed as the transfer mechanism which can be described as: 5D4(Tb3+)+7F0(Eu3+)→7F5(Tb3+)+5D1(Eu3+).5D4(Tb3+)+7F0(Eu3+)→7F5(Tb3+)+5D1(Eu3+). PL spectra and lifetime measurements support this mechanism. Due to the energy transfer, PL intensity of Eu3+Eu3+ emission increased about 40%. © 2003 The Electrochemical Society. All rights reserved.