Optical response of atomically thin materials: A focus on ellipsometric measurements

The optical constants - surface susceptibility and surface conductivity of atomically thin MoS2 can be extracted from ellipsometric parameters using a surface current model. To improve the accuracy and ensure the reproducibility of the extracted optical constants, eliminating possible effects during the measurements is critical. Here, different substrates with various incidence angles in the ellipsometric measurements have been studied and the elimination of back-reflection from substrates have been investigated. Although the ellipsometric parameters vary with the incidence angles and substrates, excellent reproducibility of the extracted surface susceptibility and surface conductivity have been achieved.