Hydrothermal synthesis and infrared to visible up-conversion luminescence of Ho3+/Yb3+ co-doped Bi2WO6 nanoparticles

In this paper, Ho3+/Yb3+ co-doped Bi2WO6 (Ho3+/Yb3+-Bi2WO6) nanoparticles were successfully synthesized by a facile hydrothermal method followed by a heat treatment process. X-ray diffraction, field emission-scanning electron microscopy, energy dispersive spectroscopy and up-conversion luminescence spectra were used to characterize the as-synthesized Ho3+/Yb3+-Bi2WO6. The effects of Yb3+ concentration on up-conversion luminescence properties were investigated. Under 980 nm laser excitation, two emission peaks centered at 546 nm and 655 nm corresponding to the F-5(4), S-5(2) and F-5(5) transitions, respectively, to the I-5(8) ground state were observed. Power studies revealed that a two-photon process was involved in the up-conversion emissions and the probable up-conversion emission mechanisms were discussed according to the energy transfer process. This study confirms that Bi2WO6 could be a potential host to achieve desired up-conversion luminescence and might be potentially applied in the fields of photocatalysis and solar cells. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.