Ge-Sb-S硫系玻璃的光谱特性及网络结构阈值行为研究

Investigation on Spectral Characteristic and Threshold Behavior of Network Structure of Ge-Sb-S Chalcogenide Glasses

用熔融淬冷技术制备了两组Ge-Sb-S三元体系的硫系玻璃,获得了在不同Ge和Sb元素含量下制备所得玻璃的一系列物化及光谱学特性,并结合拉曼光谱从玻璃微观结构层面对光学特性的变化进行了系统的分析。利用基于平均配位数(Z)的玻璃网络限制理论直观地描述了网络结构的变化趋势,发现当玻璃的Z值超过2.6时,其相应的拉曼谱上会有明显的新峰出现,说明玻璃的网络结构产生了阈值行为且结构组成发生了明显变化,具体表现为非金属化合键的减少和金属化合键的增加。玻璃网络中新功能团的形成改变了玻璃整体键能的大小,进而影响了玻璃的能带结构,从而玻璃的光学带隙(Eopg)值也随着Z值的变化表征出相应的阈值行为。

Two series of chalcogenide glasses in Ge-Sb-S ternary system were synthesized with melt-quenching method.The phycochemical properties and spectral characteristic of glasses with different content of Ge and Sb were obtained with a series of measurements,and the systematic analysis on the change of optical properties was conducted in terms of microstructure of glas-ses combined with the Raman spectra.With constraint theory based on mean coordination number（Z）,we described the variation trend of network structure directly.It was found that as long as the value of Zreaches 2.6,new vibration peaks would be formed in the Raman spectra indicating the presence of threshold behavior as well as the change of the network structure of the Ge-Sb-S glasses which could be expressed in a specific varition in the number of metal bonds and the nonmetal bonds.The appearance of new functional groups in the network have changed the total bond energy of glasses,and then affected the energy band structure of glasses representing the corresponding threshold behavior of the value of optical band gap（Eopg）.