Enhancement of the luminescent intensity of the green emitting Gd2O2CO3:Tb phosphor

Abstract: A new synthesis route to prepare well-crystallized hexagonal rare earth oxycarbonates, II-RE2O2CO3 (RE=La, Gd, and Y) in a single phase, has been established by a simple flux method. The precursor obtained by calcination of corresponding acetates was mixed with a 0.476Li2CO3–0.270Na2CO3–0.254K2CO3 eutectic mixture and heated in a pure CO2 (100%) atmosphere to obtain Eu3+- or Tb3+-doped II-RE2O2CO3 (RE=La, Gd, and Y) phosphors. Although the particle size of the oxycarbonate phosphors was in a submicron scale, they showed high emission intensities. The highest emission intensity was obtained successfully by changing the gas composition from 10%CO2–90%N2 to pure CO2 and by optimizing the flux treatment temperature, holding the particle size in a submicron scale. The maximum emission intensity was obtained at the composition of Gd2O2CO3:15at.%Tb3+, where it was 111% of that of a commercial LaPO4:Ce3+,Tb3+ phosphor. [Copyright &y& Elsevier]