Ultrabroadband mid-infrared emission from Cr ²⁺ -doped infrared transparent chalcogenide glass ceramics embedded with thermally grown ZnS nanorods

We report, for the first time to our knowledge, an ultrabroadband mid-infrared (MIR)emission in the range of 1800–2800 nm at room temperature from a Cr ²⁺ -doped chalcogenide glass ceramic embedded with pure hexagonal (wurtzite)β-ZnS nanorods and study the emission-dependent properties on the doping concentration of Cr ²⁺ . A new family of chalcogenide glasses based on (100 − x)Ge _1.5 As ₂ S _6.5 – x ZnSe (in mol.%)was prepared by melt-quenching method. The Cr ²⁺ : β-ZnS nanorods of ˜150 nm in diameter and ˜1 μm in length were grown in the Cr ²⁺ -doped glass after thermal annealing. The compositional variations of glass structures and optical properties were studied. The crystalline phase, morphology of the thermally grown nanorods, and the microscopic elemental distributions were characterized using advanced nanoscale transmission electron microscopy analyses.