Synthesis of new red emitting phosphors based on rare earth oxycarbonates

Abstract

New red emitting phosphors, hexagonal type-II La 2O 2CO 3:Eu 3+, Gd 2O 2CO 3:Eu 3+, and Y 2O 2CO 3:Eu 3+, were synthesized by the simple flux method using the 0.476Li 2CO 3–0.270Na 2CO 3–0.254K 2CO 3 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 R 2O 2CO 3:7 at.%Eu 3+ (R = La, Gd, and Y), and the relative emission intensities compared with that of the commercial Y 2O 3:Eu 3+ phosphor were 23, 27, and 22% for La, Gd, and Y, respectively.