Based on previous reports on the optical microscopy contrast of mechanically exfoliated few layer CrCl transferred on 285 nm and 270 nm SiO on Si(100), we focus on the experimental determination of an effective mean complex refractive index via a fitting analysis based on the Fresnel equations formalism. Accordingly, the layer and wavelength-dependent absorbance and reflectance are calculated. Layer and wavelength-dependent optical contrast curves are then evaluated demonstrating that the contrast is significantly high only around well-defined wavelength bands. This is validated a posteriori, by experimental UV-Vis absorbance data. The present study aims to show the way towards the most reliable determination of thickness of the 2D material flakes during exfoliation.

中文翻译：

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在菲涅耳形式主义中测定少层 CrCl 的折射率和波长相关的光学特性

基于先前关于在Si(100) 上转移到 285 nm 和 270 nm SiO上的机械剥离的几层 CrCl 的光学显微镜对比度的报告，我们专注于通过基于菲涅耳的拟合分析来实验确定有效平均复折射率方程形式主义。因此，计算层和波长相关的吸收率和反射率。然后评估层和波长相关的光学对比度曲线，证明仅在明确定义的波长带附近对比度显着高。这是通过实验 UV-Vis 吸光度数据后验验证的。本研究旨在展示在剥离过程中最可靠地确定二维材料薄片厚度的方法。