In the last few decades, I-V-VI group is considered as one of the finest combinations for various electrical as well as optical applications. The present report discussed the photo-induced transformation in both optical and structure-related properties of Sb/AgSe bilayer thin films of 645 nm. The Sb/AgSe bilayer films were laser irradiated by 532 nm laser for various time scales. The presence of AgSe orthorhombic phase was verified through X-ray diffraction and Raman analysis. The increase in crystallite size reduced the strain in the films due to laser irradiation-induced intermixing and modified the optical parameters. The decrement in transmission and shift in absorption edge shows the photodarkening mechanism in the films with Sb diffusion into the AgSe layer. The decrement in the bandgap with laser irradiation is associated with the change in the density of states. The non-linear refractive index of Sb/AgSe film increased from 10.62 × 10 to 12.77 × 10 esu upon 60 min laser irradiation. The 3-order non-linear susceptibility also increased (9.73 × 10 esu to 11.98 × 10 esu) upon 60 min laser irradiation. The hydrophobic nature of the film surface remained unchanged with laser treatment. The density functional investigation inferred the changes associated with the band structure and density of states. Such enhanced nonlinear optical entities of the irradiated films might be suitable for optoelectronic and compact non-linear device applications.

中文翻译：

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Sb/Ag2Se 异质结层在不同激光时间下的光诱导界面混合，用于调整其光电应用的线性非线性光学特性：实验和计算研究

在过去的几十年中，IV-VI 组被认为是各种电气和光学应用的最佳组合之一。本报告讨论了 645 nm Sb/AgSe 双层薄膜的光学和结构相关特性的光诱导转变。 Sb/AgSe 双层薄膜采用 532 nm 激光进行不同时间尺度的激光照射。通过X射线衍射和拉曼分析验证了AgSe正交相的存在。微晶尺寸的增加减少了由于激光照射引起的混合而导致的薄膜应变，并改变了光学参数。透射率的下降和吸收边的移动表明了 Sb 扩散到 AgSe 层中薄膜中的光暗化机制。激光照射引起的带隙减小与态密度的变化有关。激光照射 60 分钟后，Sb/AgSe 薄膜的非线性折射率从 10.62 × 10 esu 增加到 12.77 × 10 esu。激光照射 60 分钟后，三阶非线性磁化率也增加（9.73 × 10 esu 至 11.98 × 10 esu）。激光处理后薄膜表面的疏水性保持不变。密度泛函研究推断了与能带结构和态密度相关的变化。辐照薄膜的这种增强的非线性光学实体可能适用于光电和紧凑型非线性器件应用。