Detecting MoS2 and MoSe2 with optical contrast simulation

作     者：Xiaohe Zhang Hiroyo Kawai Jing Yang Kuan Eng Johnson Goh 

作者机构：Victoria Junior College Institute of Materials Research and Engineering A*STAR (Agency for Science Technology and Research) Department of Physics Faculty of Science National University of Singapore 

出 版 物：《Progress in Natural Science:Materials International》 (自然科学进展·国际材料(英文))

年 卷 期：2019年第29卷第6期

页      面：667-671页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 070301[理学-无机化学] 

基　　金：funded by A*STAR Pharos Grant No. 1527000016 and 1527000017 

主　　题：2D materials Optical imaging Substrate Fresnel law 

摘      要：Optical imaging is a promising method to identify and locate 2D materials efficiently and non-invasively. By putting a 2D material on a substrate, the nanolayer will add to an optical path and create a contrast to the case when the nanolayer is absent. This optical contrast imaging can be used to identify the 2D material and its number of layers. To make the optical imaging process in the laboratories an effective tool, Fresnel Law as a model was used to simulate the optical imaging results of 2D materials(graphene, Mo S2 and MoSe2) on top of different thickness of SiO2and Si wafer in the present investigation. The results provide the details of the optimal conditions(optimal light wavelength and optimal SiO2thickness) to identify and locate single to few 2D nanolayers, which can be used directly in laboratories. The optical contrasts of 1–5 layers of molybdenum disulfide(MoS2) and molybdenum diselenide(MoSe2) were simulated. To the best of our knowledge, it is the first time that the optical contrast results of MoSe2have been reported. In particular, this work highlights the sensitivity of the model on the accuracy of the refractive indices used. It is demonstrated that through computational modeling that optical contrast can allow effective determination of number of layers in few layer 2D materials.