Bright white up-conversion emission from Er~(3+)/Ho~(3+)/Tm~(3+)/Yb~(3+) co-doped YVO_4 phosphors

摘要

Er~(3+)/Ho~(3+)/Yb~(3+)/Tm~(3+) co-doped YVO_4 phosphors were synthesized by the conventional solid-state reaction. Under 980 nm laser diode excitation, intense red, green and blue up-conversion emissions were observed for the Yb~(3+)/Er~(3+), Yb~(3+)/Ho~(3+) and Yb~(3+)/Tm~(3+) couples in the YVO_4 host, respectively, which were due to the successive energy transfer from Yb~(3+) to Er~(3+), Ho~(3+) or Tm~(3+). Bright white luminescence upon 980 nm near-infrared excitation can be observed for the sample at the optimum chemical composition of YVO_4:10%Yb~(3+)/l%Tm~(3+)/0.3%Ho~(3+)/0.2%Er~(3+). Under different excitation pump powers, the obtained optimal color coordinate (0.323,0.325) is very close to the standard white light (0.333,0.333) coordinate.