Synthesis of new red emitting phosphors based on rare earth oxycarbonates

New red emitting phosphors, hexagonal type-II La2O2CO3:Eu3+, Gd2O2CO3:Eu3+, and Y2O2CO3:Eu3+, were synthesized by the simple flux method using the 0.476Li2CO3-0.270Na2CO3-0.254K2CO3 eutectic mixture, and their photoluminescent properties were characterized. The red emission was observed in each sample and their particle sizes were in a submicron scale. The excitation wavelength of their charge transfer bands depended on the difference of the electronegativities of rare earth elements constituting the host lattices. In these phosphors, the highest emission was obtained at the composition of R2O2CO3:7 at.%Eu3+ (R = La, Gd, and Y), and the relative emission intensities compared with that of the commercial Y2O3:Eu3+ phosphor were 23, 27, and 22% for La, Gd, and Y, respectively