Research of optical absorption and luminescence spectra of double-perovskite calcium tungstate co-doped with Yb~(3+)/Ho~(3+)

摘要

AbstractHo3+/Yb3+co-doped Ca3WO6phosphors synthesized via a conventional solid-state reaction method and characterized structurally by X-ray diffraction analysis. For the investigation of particle size and the surface morphology of the prepared material the field emission scanning electron microscopy have been performed. No absorption band around 980 nm has been observed in the Ho3+doped phosphors whereas a broad band around 980 nm in the Ho3+/Yb3+co-doped phosphors corresponding to2F5/2→2F7/2absorption transition of Yb3+ion has been detected. Up-conversion emission band have been observed in the visible region upon excitation with a 980 nm laser diode. The thermal stability of luminescence of Ca3WO6:Ho3+/Yb3+was also investigated and the activated energy was deduced to be 0.173 eV, which shown good thermal stability. The study provides deep insights into the understanding of bidirectional energy transfer in UC mechanism, offering the possibility for applications in color displays and anti-counterfeiting techniques.