Correlation‐free reflection diagnostics of graphene‐like surface layers in the infrared region

Abstract

New diagnostics possibilities for graphene‐like (two‐dimensional absorbing) ultrathin films on dielectric substrates by integrating ellipsometric and reflectance measurements are analyzed. The analysis is based on the analytical theory which has been developed in the framework of a long‐wavelength approximation. Importantly, the new method allows simultaneously (without correlation) to determine the thickness and optical constants of two‐dimensional materials in the infrared region. Another interesting feature of this reflection technique lies in the fact that for data handling the traditional model‐based regression analysis is not in use. The inversion problem is resolved on the basis of an analytical approach which has no need of initial guesses for the desired parameters. The results are also of interest as suitable starting points for non‐approximated numerical iterative methods where the proper choice of the initial data plays a crucial role. The presented method is tested using a numerical simulation. Copyright © 2015 John Wiley & Sons, Ltd.