ABSTRACT Amorphous samples of Se58Ge27Pb15 and Se58Ge24Pb18 glasses were prepared using the melt quenching method. Thin films of samples were deposited using the vacuum evaporation method. These films were illuminated with Nd: YAG 532 nm green laser radiation. The samples were structurally characterised using X-ray Diffraction (XRD) and Energy-dispersive X-ray analysis. XRD indicated an increase in the crystallinity of samples on laser irradiation. The samples were optically tested through absorption, reflection and transmission spectra recorded on UV-vis spectrophotometer. The obtained values of energy band gap, refractive index, extinction coefficient and Urbach energy of the films were compared both before and after laser exposure. Furthermore, it was found that sample thickness also changes on laser irradiation. The band gap of the samples was found to decrease laser irradiation in Se58Ge27Pb15thin films, while for Se58Ge24Pb18 thin film samples, an unexpected increase in band gap was observed at a laser irradiation time of 8 min. The variable behaviour of band gap has been explained on the basis of Mott and Davis model and heteropolar bond formation.

中文翻译：

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激光诱导的光学改性 Se58Ge27Pb15 和 Se58Ge24Pb18 薄膜

摘要 Se58Ge27Pb15 和Se58Ge24Pb18 玻璃的非晶样品是用熔体淬火方法制备的。使用真空蒸发方法沉积样品薄膜。这些薄膜用 Nd:YAG 532 nm 绿色激光辐射照射。使用 X 射线衍射 (XRD) 和能量色散 X 射线分析对样品进行结构表征。XRD 表明样品在激光照射下的结晶度增加。通过在紫外-可见分光光度计上记录的吸收、反射和透射光谱对样品进行光学测试。比较激光曝光前后薄膜的能带隙、折射率、消光系数和Urbach能量值。此外，发现样品厚度也会随着激光照射而变化。发现样品的带隙减少了 Se58Ge27Pb15 薄膜中的激光照射，而对于 Se58Ge24Pb18 薄膜样品，在 8 分钟的激光照射时间观察到带隙的意外增加。带隙的可变行为已在莫特和戴维斯模型和异极键形成的基础上得到解释。