The photoluminescence properties of Pr3+-Yb3+ co-doped gallo-germanate glasses and glass ceramics as energy converter

Rare earth ions are efficient candidates for converting solar photons to suitable counterparts that are available for the commercially Si-based photovoltaic solar cells, which are often enabled in glasses and glass ceramics (GCs). Herein, Pr3+-Yb3+ ions co-doped 65GeO2-15Ga2O3-10BaO-10LaF3 glasses were studied and corresponding GCs were obtained by heat treatment under different temperature-time conditions. Gallo-germanium oxide nanocrystals (NCs) precipitation has been confirmed by X-ray diffraction and scanning electron microscopy. Excitation and emission spectra, as well as lifetime decay curves of all glasses and GCs were recorded in the visible and near-infrared region. Energy transfer efficiencies and quantum yields were calculated according to the spectra. The results show that the glass has excellent energy conversion characteristics with a maximum 20.2% quantum yield in near-infrared down-conversion emission and the quantum yield has been enhanced to 38.9% in GCs. Results suggest that the near-infrared emission efficiency could be significantly enhanced by NCs crystallization process and the studied system had potential applications in energy conversion for Si-based solar cells.