Photoluminescence properties of Tb3Al5O12:Ce3+ garnet synthesized by the metal organic decomposition method

Abstract Tb 3 Al 5 O 12 :Ce 3+ garnet (TAG:Ce 3+ ) phosphor was synthesized by the metal organic decomposition (MOD) method and subsequent calcination at T c = 800–1200°C for 1 h in air. The effects of Ce 3+ concentration on the phosphor properties were investigated in detail using X-ray diffraction (XRD) analysis, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and PL decay measurements. The maximum intensity in the Ce 3+ yellow emission was observed at the Ce 3+ concentration of ∼0.20%. PLE and PL decay measurements suggested an evidence of the energy transfer from Tb 3+ to Ce 3+ . Calcination temperature dependence of the XRD and PL intensities yielded an energy of ∼1.5 eV both for the TAG formation in the MOD process and for the optical activation of Ce 3+ in its lattice sites. Temperature dependences of the PL intensity for the TAG:Ce 3+ yellow-emitting and K 2 SiF 6 :Mn 4+ red-emitting phosphors were also examined for the future solid-state lighting applications at T = 20–500 K in 10-K steps. The data of TAG:Ce 3+ were analyzed using a theoretical model with considering a reservoir level of E t ∼9 meV, yielding a quenching energy of E q ∼0.35 eV, whereas the K 2 SiF 6 :Mn 4+ red-emitting phosphor data yielded a value of E q ∼1.0 eV. The schematic energy-level diagrams for Tb 3+ and Ce 3+ were proposed for the sake of a better understanding of these ions in the TAG host.