Fabrication and Structural Characterization of Se-Ge Chalcogenide Glasses by Means of Melt Quenching Technique

The structural and optical characterization of Se-Ge alloys during melt quenching technique was the goal of this study. In this regards, five different samples of Se۱۰۰-xGex (x= ۱۰, ۲۰, ۳۰, ۴۰, ۵۰) were prepared by conventional melt quenching in quartz ampoule. The produced samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The results showed that the glass forming ability of Se۷۰Ge۳۰ and Se۵۰Ge۵۰ is so low and the structures of these alloys after quenching are combination of amorphous, GeSe۲ and GeSe compounds. Although the structure of as-quenched Se۹۰Ge۱۰, Se۸۰Ge۲۰ and Se۶۰Ge۴۰ is fully amorphous, only Se۶۰Ge۴۰ shows IR transmittance (with higher ۵۵% transmittance between ۰.۸-۱۱ µm). The reflective index of this glass was in the range of ۳.۰ to ۳.۳ and decrease with increasing the wavelength. The Fermi energy, Urbach energy, indirect and direct band gaps values of Se۶۰Ge۴۰ glass were estimated about ۰.۲۸۸۳, ۰.۱۵۲۶, ۱.۳۴۵ and ۱.۲۸ e.V, respectively.

Keywords:

Chalcogenide glass , Se , Ge , IR transmittance