Research on the photoluminescence and up-conversion luminescence properties of Y2Mo4O15: Yb, Ho under 454 and 980 nm excitation
- Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China)
Highlights: • In this paper, Y{sub 2}Mo{sub 4}O{sub 15}:Yb, Ho phosphors were synthesised using the conventional solid-state reaction method for the first time, and its photoluminescence and up-conversion emission properties were characterised for the first time under 454 and 980 nm excitation. The special red UCL mechanism was also analysed for the first time. • We observe an abnormal red UCL in Y{sub 2}Mo{sub 4}O{sub 15}:Yb, Ho under 980 nm excitation. • The reducing of decay time of {sup 5}I{sub 6} states is responsible for the red UCL. • Very weak {sup 5}I{sub 6} → {sup 5}I{sub 8} IR emission further confirm the short decay time of {sup 5}I{sub 6} in Y{sub 2}Mo{sub 4}O{sub 15}:Yb, Ho. - Abstract: Y{sub 1.8-x}Yb{sub 0.2}Ho{sub x}Mo{sub 4}O{sub 15} (x = 0.005, 0.01, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64) phosphors were synthesised at 700 °C by using a solid-state reaction method. The samples were characterised by X-ray diffraction, diffuse reflectance spectra, photoluminescence and up-conversion emission spectra. The photoluminescence spectra of Y{sub 2}Mo{sub 4}O{sub 15}:Yb, Ho shows extremely strong green down-shift luminescence corresponding to the {sup 5}F{sub 4}, {sup 5}S{sub 2} → {sup 5}I{sub 8} transition of Ho{sup 3+} ions with I{sub g}/I{sub r} > 20 under 454 nm excitation. While at 980 nm excitation, Y{sub 2}Mo{sub 4}O{sub 15}:Yb, Ho sample exhibits unusual red up-conversion luminescence along with a very weak green emission (I{sub r}/I{sub g} = 6.4), which is resulted from the severe non-radiative relaxation ({sup 5}I{sub 6} → {sup 5}I{sub 7}) process due to the very short decay time of {sup 5}I{sub 6} states of Ho{sup 3+} ions. The mechanism of down-shift luminescence is the electrical dipole – dipole transitions. The quenching concentration for down-shift luminescence is higher than that for up-conversion luminescence, which results from the effects of different luminescence processes and large distance between doped rare earth ions in Y{sub 2}Mo{sub 4}O{sub 15}. The different luminescence mechanism and color performance are also studied.
- OSTI ID:
- 22805369
- Journal Information:
- Materials Research Bulletin, Vol. 98; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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