Multi-Phase Induced Ultra-Broad 1100-2100 nm Emission of Ni2+ in Nano-Glass Composites Containing Hybrid ZnGa2O4 and ZnF2 Nanocrystals

Abstract A new type of Ni2+-doped dual-phase glass ceramics (GCs) is developed by a simple one-step thermal-induced crystallization process. The GCs thus obtained are embedded simultaneously with hybrid ZnGa2O4 and ZnF2 nanocrystals (NCs). When pumped by a readily available 808 nm laser diode, an ultra-broad near-infrared (NIR) emission in a range of 1100-2100 nm is observed at room temperature. The NIR emission band with a full-width-at-half-maximum (FWHM) of more than 450 nm is comparable to the largest value ever reported in Ni2+-doped GCs, and much broader than those of single-phase GCs embedded with either pure ZnGa2O4 or ZnF2 NCs. The microscopic morphologies of the embedded hybrid NCs, and especially the distribution of Ni2+ in the dual-phase GCs are studied by analytical transmission electron microscopy (TEM). The intriguing photoluminescence properties of Ni2+ are thoroughly investigated by steady-state and time-resolved emission spectra. The GCs demonstrated herein hold promise as broadband solid-state NIR-light sources.