Compositional dependence of the optical properties of novel Ge-Ga-Te-CsI far infrared transmitting chalcohalide glasses system

Guoxiang Wang (1) , Qiuhua Nie (1) , Mohamed Barj (2) , Xunsi Wang (1) , Shixun Dai (1) , Xiang Shen (1) , Tiefeng Xu (1) , Xianghua Zhang (3)

1 The State Key Laboratory Base of Novel Functional Materials and Preparation Science
2 LASIRE - Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516
3 ISCR - Institut des Sciences Chimiques de Rennes

A systematic series of (Ge₁₅Ga₁₀Te₇₅)_1−x(CsI)_x (x=0, 5, 10, 15 at%) far infrared transmitting chalcohalide glasses were prepared by the traditional melt-quenching method. The physical, thermal and optical properties were determined. The allowed direct transition and indirect transition of samples were calculated according to the Tauc equation. The results show that glass transition temperatures (T_g) were in the range 133-175 °C, with ΔT values between 81 and 130 °C. The highest values of metallization criterion (0.244) and energy gap (1.191 eV) were obtained for (Ge₁₅Ga₁₀Te₇₅)₈₅(CsI)₁₅. When the dissolved amount of CsI increased from 0 to 15 at%, the direct optical band gap and indirect optical band gap were in the ranges 0.629-1.075 eV and 0.438-0.524 eV, respectively. The Ge-Ga-Te-CsI glasses have an effective transmission window between 1.7 and 25 μm, encompassing the region of interest for bio-sensing applications.

Mots clés: Chalcogenides; Glasses; Optical properties

Domaines: Chimie théorique et/ou physique; Matériaux

Guoxiang Wang, Qiuhua Nie, Mohamed Barj, Xunsi Wang, Shixun Dai, et al.. Compositional dependence of the optical properties of novel Ge-Ga-Te-CsI far infrared transmitting chalcohalide glasses system. Journal of Physics and Chemistry of Solids, 2011, 72 (1), pp.5 - 9. ⟨10.1016/j.jpcs.2010.10.018⟩. ⟨hal-00564227⟩