Correlation between luminescent properties and local coordination environment for erbium dopant in yttrium oxide nanotubes

Abstract

The local dopant coordination environment and its effect on the photoluminescent (PL) spectral features of erbium-doped yttrium oxide nanotubes (NTs) were probed by synchrotron-based x-ray diffraction (XRD), x-ray absorption near-edge spectroscopy (XANES), and extended x-ray absorption fine structure (EXAFS). XRD, XANES, and EXAFS data demonstrate that single phase solid solutions of Y(2−x)ErxO3 were formed at 0≤x<0.4 and 1.2<x≤2, and the valence state of Er ions in the Y2O3 NTs is +3. The x-ray spectroscopic data clearly show that the erbium dopants largely reside in two types of sites in the Y2O3 host material, both of which possess a well-defined intermediate-range structure, and that the doping of erbium into Y2O3 does not cause a loss in intermediate-range order and crystallinity in the Er3+:Y2O3 NTs. This well-defined distribution of erbium doping inside the Y2O3 matrix correlates well with the observed sharp and well-resolved PL behavior of these Er3+:Y2O3 NTs at around 1.535 μm.