A Comparative Study of SiO2:Tb3+@Gd2O3:Eu3+ and Its Inverted Tb3+-Eu3+ Core-Shell Phosphors.

ABSTRACT

How to effectively improve energy transfer efficiency and luminous intensity inspired us to synthesize a series of SiO2x%Tb3+@Gd2O3y%Eu3+ samples, study their luminescence properties and interfacial energy transfer (IET), and compare with SiO2x%Eu3+@Gd2O3y%Tb3+. The results show that SiO2x%Tb3+@Gd2O3y%Eu3+ can exhibit adjustable multicolor luminescence from red to green at different concentrations of Eu3+ and Tb3+ or under different excitation wavelengths, and there exists efficient IET from Tb3+ to Eu3+ in SiO2x%Tb3+@Gd2O3y%Eu3+ and SiO2x%Eu3+@Gd2O3y%Tb3+, which improves the energy transfer efficiency and luminous intensity. In addition, the luminescence properties are different between SiO23%Tb3+@Gd2O33%Eu3+ and SiO23%Eu3+@Gd2O33%Tb3+, and the energy transfer efficiency of Tb3+ → Eu3+ in SiO23%Tb3+@Gd2O33%Eu3+ is obviously higher than that in SiO23%Eu3+@Gd2O33%Tb3+. The present study not only developed a kind of multicolor luminescent phosphor but also offered an important new strategy for improving the energy transfer efficiency and luminescent intensity.