Intense blue upconversion emission in Tm3+/Yb3+ codoped Gd2O3 phosphor

The Gd2O3 nanophosphors codoped with Yb3+/Tm3+ and Yb3+/Tm3+/Li+ ions have been successfully synthesized by conventional solid-state reaction method. Upon 980 nm laser diode excitation, the upconversion emission spectra of the synthesized phosphors have been recorded. The observed spectra show intense blue bands at ti 477 nm, ti 489 nm and one red band at 656 nm, which are assigned to (1)G(4(a)) -. H-3(6,) 1G(4(b)) -. H-3(6) and (1)G(4(b)) -.F-3(4) transitions of Tm3+ ion respectively. The absorption spectrum of the prepared phosphor has been recorded using UV-Vis-NIR spectrophotometer. The mechanism involved in UC emission process have been analysed with help of energy level diagram and pump power study. Moreover, the CIE colour coordinates of synthesized phosphors lies in blue region which indicates that the prepared phosphors have potential applications in NIR to Visible upconversion and in blue LEDs. (c) 2019 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the Third International Conference on Materials Science (ICMS2020).