Synthesis and photoluminescence characteristics of a novel Eu and Tb doped Li2MoO4 phosphor. (September 2021)

• Record Type: Journal Article
• Authors: Souadi, G.; Kaynar, U.H.; Ayvacikli, M.; Coban, M.B.; Oglakci, M.; Canimoglu, A.; Can, N.
• Is Part Of: Applied radiation and isotopes. Volume 175(2021)
• Publication Date: 2021-09
• Subjects: Li2MoO4 -- Gel-combustion method -- Photoluminescence -- Concentration quenching -- Critical distance; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2021.109820
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: Li2 MoO4 :x Eu 3+ and Li2 MoO4 :xTb 3+ phosphors, where x = 0.5, 1, 2, 3, 5 and 7 wt%, were synthesized through a gel-combustion method. The XRD data reveals that Eu 3+ and Tb 3+ doped Li2 MoO4 phosphors exhibit a Rhombohedral structure belonging to the space group R3 which matched well with the standard JCPDS files (No.012-0763). We present photoluminescence (PL) spectra from Eu and Tb doped Li2 MoO4 under 349 nm Nd:YLF pulses laser excitation over the temperature range of 10–300 K. Undoped Li2 MoO4 shows a wide broad band around 600 nm because of the intrinsic PL emission of tetrahedral of M o O 4 2 − which was in good agreement with previous findings. Under the excitation of 394 nm, the as-synthesized phosphors exhibited sharp and strong intensity PL emission signals in the red (612 nm, 5 D0 → 7 F2 transition) and green (544 nm, 5 D4 → 7 F5 transition), respectively. The critical doping concentration of Eu 3+ and Tb 3+ ions in the Li2 MoO4 were estimated to be 2 wt%. The concentration quenching phenomena were discussed, and the critical distances for energy transfer have also been evaluated by the concentration quenching. Highlights: ➢ A series of Eu and Tb doped host sensitized Li2 MoO4 were synthesized ➢ Optimal doping concentration for all samples was 2 mol% ➢ Photoluminescence properties of Eu 3+ and Tb 3+ activated Li2 MoO4 phosphors are discussed ➢ Concentration quenching mechanism was discussed