The distribution of rare earth ions in a γ-Ga2O3 nanocrystal-silicate glass composite and its influence on the photoluminescence properties

Abstract

The distribution of rare earth ions (REs: Yb³⁺, Er³⁺, Eu³⁺ and Nd³⁺) in a nanostructured silicate glass ceramic containing a wide bandgap γ-Ga₂O₃ nanospinel is revealed using well-prepared electron-transparent samples and an analytical transmission electron microscope (TEM). It is found that the REs accumulate preferentially in the γ-Ga₂O₃ nanocrystals formed, and the REs of small ionic radii (Yb³⁺ and Er³⁺) exhibit higher doping efficiency in the nanocrystals than those of larger ionic radii (Eu³⁺ and Nd³⁺). The incorporation of REs into the γ-Ga₂O₃ nanospinels leads to a significant modification of their photoluminescence characteristics including the emission intensity, peak wavelength, bandwidth and decay lifetime of the dopants. The possible causes are discussed.