A Facile Method for Precise Layer Number Identification of Two-Dimensional Materials through Optical Images

Abstract

Optical microscopy is believed to be an efficient method for identifying layer number of two-dimensional 2D materials. However, since illuminants, cameras and their parameters are different from lab to lab, it is impossible to identify layer numbers just by comparing a given optical image with standard or calculated images under standard conditions. Here we reported an image reconstruction method, converting raw optical images acquired by arbitrary illuminants and cameras into reconstructed images at specified illuminant and specified camera. After image reconstruction, the color differences of each layer number roughly equaled those calculated under specified condition. By comparing the color differences in reconstructed image with those calculated under specified condition, the layer numbers of 2D materials in our lab and published papers, including MoS2, WS2 and WSe2, were ambiguously identified. This study makes optical microscopy a precise method for identifying layer numbers of 2D materials on known substrate.

References in corpus (11)

• Electric Field Effect in Atomically Thin Carbon Films
• Two Dimensional Atomic Crystals
• Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils
• Making graphene visible
• The Renaissance of Black Phosphorus
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Visibility of dichalcogenide nanolayers
• Rapid and reliable thickness identification of two-dimensional nanosheets using optical microscopy
• Mapping of Low-Frequency Raman Modes in CVD-Grown Transition Metal Dichalcogenides: Layer Number, Stacking Orientation and Resonant Effects
• Optical thickness determination of hexagonal Boron Nitride flakes
• Excitonic Resonance Effects and Davydov Splitting in Circularly Polarized Raman Spectra of Few-Layer WSe2