Ge5AsxTe95-x amorphous thin films (x=20∼60) have been deposited by thermal evaporation and the change of their optical parameters—like refractive index and optical bandgap as a function of thermal annealing time—have been studied with an aim to screen the composition of the film with stable optical and thermal properties for applications in optical waveguide devices. The film with a composition around x=38.0 was found to be stable, while the optical band gap and refractive index decreases in the films with x 38.0. Further structural characterization showed no any observable changes of the Raman spectra in the as-prepared and annealed Ge5.2As38.0Te56.8 film, confirming the stability of the optical and thermal properties in this composition.

中文翻译：

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Ge-As-Te 薄膜组成中热稳定性的依赖性

Ge5AsxTe95-x 非晶薄膜 (x=20∼60) 已通过热蒸发沉积，并研究了它们的光学参数（如折射率和光学带隙作为热退火时间的函数）的变化，目的是筛选具有稳定光学和热性能的薄膜组成，可用于光波导器件。发现组成约为 x=38.0 的薄膜是稳定的，而 x 为 38.0 的薄膜中的光学带隙和折射率降低。进一步的结构表征表明，在制备和退火的 Ge5.2As38.0Te56.8 薄膜中，拉曼光谱没有任何可观察到的变化，证实了该组合物的光学和热性能的稳定性。