Spectroscopic peculiarities of excitation and emission processes as well as relaxation dynamic of excited states in doubly and triply doped Gd3Ga3Al2O12:Ln3+ (Ln3+ = Eu3+, Tb3+, Ce3+) crystals

Spectroscopic properties of Gd3Ga3Al2O12 (GGAG) single crystals co-doped with various configurations of (Eu + Tb); (Eu + Ce); + Ce) and (Eu + Tb + Ce) ions have been investigated. The effect of distinct Ln(3+) co-doping variations on luminescence of garnet crystals was studied using the different excitation wavelengths. The Ln(3+)-Ln(3+) and host-Ln(3+) interplays have been considered in doubly and triply doped GGAG:Ln(3+). The crystals containing cerium ions are characterized by mainly broadband emission in the 450-750 nm spectral region that is adequately modified in green and red spectral range in the samples co-doped with terbium and europium, respectively. The Eu3+ luminescence in materials under study is selectively excited employing solely f-f europium transitions. Contrary to that, emission of terbium and cerium occur as result of interaction with Gd3+ and adjacent co-dopants.