Abstract Amorphous Ge20Se76Sn4 thin films of thickness ~150 nm were prepared, from bulk Ge20Se76Sn4, by thermal evaporation technique. The differential scanning calorimetry analysis of bulk Ge20Se76Sn4 exhibits one glass transition, one crystallization peak, and one melting point. The inclusion of Sn by substituting Se or Ge-atoms into the Ge–Se matrix has been studied using energy-dispersive spectral X-ray, and Fourier-transform infrared spectroscopy. The X-ray diffraction affirms that films annealed at annealing temperature (Ta) ≤ 553 K are amorphous; meanwhile, films annealed at Ta≥ 603 K are crystalline. It was found that the annealing process can be used to tune the linear and nonlinear optical parameters and constants. The decrease in the indirect optical bandgap energy (Eg) with an increase in Ta for Ta ≥ 603 K could be ascribed to the increase in the crystallinity and increasing the density of defects in the bandgap. The estimated Eg were correlated with the refractive index (n) using seven different approaches and the average value of n was increased as Ta increased. It is suggested that the structural, and optical characteristics of the thermally evaporated Ge20Se76Sn4 thin films can be tuned and engineered by the annealing process. Profound analysis of optical parameters for the Ge20Se76Sn4 thin films suggests the utilization of these glasses for numerous photonic applications.

中文翻译：

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热蒸发退火 Ge20Se76Sn4 薄膜的结构和光学特性

摘要 采用热蒸发技术从块体 Ge20Se76Sn4 制备了厚度 ~150 nm 的非晶 Ge20Se76Sn4 薄膜。块状 Ge20Se76Sn4 的差示扫描量热分析显示出一个玻璃化转变、一个结晶峰和一个熔点。已经使用能量色散光谱 X 射线和傅里叶变换红外光谱研究了通过将 Se 或 Ge 原子取代到 Ge-Se 基质中来包含 Sn。X 射线衍射证实在退火温度 (Ta) ≤ 553 K 下退火的薄膜是无定形的；同时，在 Ta≥603 K 退火的薄膜是结晶的。发现退火过程可用于调整线性和非线性光学参数和常数。当 Ta ≥ 603 K 时，随着 Ta 的增加，间接光学带隙能量 (Eg) 的降低可归因于结晶度的增加和带隙中缺陷密度的增加。估计的 Eg 与使用七种不同方法的折射率 (n) 相关，n 的平均值随着 Ta 的增加而增加。建议可以通过退火工艺调整和设计热蒸发 Ge20Se76Sn4 薄膜的结构和光学特性。对 Ge20Se76Sn4 薄膜光学参数的深入分析表明，这些玻璃可用于众多光子应用。估计的 Eg 与使用七种不同方法的折射率 (n) 相关，n 的平均值随着 Ta 的增加而增加。建议可以通过退火工艺调整和设计热蒸发 Ge20Se76Sn4 薄膜的结构和光学特性。对 Ge20Se76Sn4 薄膜光学参数的深入分析表明，这些玻璃可用于众多光子应用。估计的 Eg 与使用七种不同方法的折射率 (n) 相关，n 的平均值随着 Ta 的增加而增加。建议可以通过退火工艺调整和设计热蒸发 Ge20Se76Sn4 薄膜的结构和光学特性。对 Ge20Se76Sn4 薄膜光学参数的深入分析表明，这些玻璃可用于众多光子应用。