Using spectroscopic ellipsometry from the midinfrared (0.03 eV) to the deep ultraviolet (6.5 eV), the authors determined the thickness dependence of the dielectric function for ZnO thin layers (5–50 nm) on Si and quartz in comparison to bulk ZnO. They observed a small blueshift of the band gap ( ∼80 meV) in thin ZnO layers due to quantum confinement, which is consistent with a simple effective mass theory in an infinite potential well. There is a drastic reduction in the excitonic effects near the bandgap, especially for thin ZnO on Si, which not only affects the excitonic absorption peak but also lowers the high-frequency dielectric constant by up to 40%. No significant change of the phonon parameters (except an increased broadening) in thin ZnO layers was found.

中文翻译：

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ZnO 层中红外晶格吸收和激子吸收对通过原子层沉积生长的 Si 和 SiO2 的厚度依赖性

使用从中红外 (0.03 eV) 到深紫外 (6.5 eV) 的光谱椭偏法，作者确定了与块状 ZnO 相比，Si 和石英上的 ZnO 薄层 (5-50 nm) 的介电函数的厚度依赖性。由于量子限制，他们在薄 ZnO 层中观察到带隙的小蓝移（~80 meV），这与无限势阱中的简单有效质量理论一致。带隙附近的激子效应急剧下降，特别是对于 Si 上的薄 ZnO，这不仅影响激子吸收峰，而且使高频介电常数降低高达 40%。没有发现薄 ZnO 层中声子参数的显着变化（除了增加的展宽）。