Bright white upconversion luminescence from Er3+-Tm3+-Yb3+ doped CaSnO3 powders

Bright white upconversion luminescence from Er3+-Tm3+-Vb(3+) doped CaSnO3 powders is obtained under the diode laser excitation of 980 nm. It is composed of three primary colors of red, green and blue emissions, which originate from the transitions of F-4(9/2) -> I-4(15/2), (H-2(11/2), S-4(3/2)) -> I-4(15/2) of Er3+ ions and (1)G(4) -> H-3(6) of Tm3+ ions, respectively. The efficient upconversion emission is attributed to the energy transfer between Yb3+ and Er3+ or Tm3+ ions. Moreover, it is observed that Tm3+ acts as the quenching center for the green upconversion luminescence from Er3+ ions, and the sensitizer for the red and blue luminescence when the Tm3+ doping content is less than 0.3 mol%. This is interpreted in terms of the efficient energy transfer between Tm3+ and Er3+ ions. The calculated color coordinates fall within the white region in the standard 1931 CIE chromaticity diagram, indicating the potential applications of Er3+-Tm3+-Yb3+ doped CaSnO3 in the field of displaying and lasers, etc. (C) 2011 Elsevier B.V. All rights reserved.