Luminescent Properties of Nanopowder and Single‐Crystalline Films of TbAG:Ce Garnet. Issue 8 (14th February 2020) - Bolek, Paulina
Abstract : Herein, the luminescence properties of nanopowders (NPs), thin NP film and single‐crystalline film (SCF) of TbAG:Ce garnet are compared. The NPs are prepared by the combustion synthesis. NP films with thickness of 300 nm are prepared using the spin‐coating method. SCFs are grown by liquid phase epitaxy. Structure and morphology of NPs, NP films, and SCFs are studied using scanning electron microscopy and X‐ray diffraction. The luminescence properties of these samples are characterized by cathodoluminescence (CL) and photoluminescence (PL). CL spectra of the TbAG:Ce NP, NP films, and SCFs show the dominant Ce 3+ emission in the garnet host. Meanwhile, in the PL spectra of NPs, the complex UV emission band is also observed. Its origin is related to 1) thermodynamic instability of TbAG garnet phase and formation of TbAP:Ce perovskite phase under conditions of NP preparation; 2) formation of UV emitting centers in both TbAG and TbAP hosts. This UV emission band is fully absent in TbAG:Ce SCF. Therefore, TbAG SCFs are useful objects for studying the luminescence of this garnet and different dopants in them. Furthermore, both TbAG:Ce NP films and SCFs are applicable for producing cathodoluminescent and scintillating screens with thickness in the μm/sub μm ranges. Abstract : Cathodoluminescence spectra of TbAG:Ce NP, NP film, and SCF show the dominant Ce 3+ band peaking at 550 nm in the garnet host without any sign of the Ce 3+ emission of other than garnet phases and the luminescence of the defect‐related centers. That is very suitable for the scintillation applications of such crystalline form of TbAG:Ce garnet.