Investigation of multilayer domains in large-scale CVD......
CVD graphene is a promising candidate for optoelectronic applications due to its high quality and high yield. However, multi-layer domains could inevitably form at the nucleation centers during the growth. Here, we propose an optical imaging technique to precisely identify the multilayer domains and also the ratio of their coverage in large-scale CVD monolayer graphene. We have also shown that the stacking disorder in twisted bilayer graphene as well as the impurities on the graphene surface could be distinguished by optical imaging. Finally, we investigated the effects of bilayer domains on the optical and electrical properties of CVD graphene, and found that the carrier mobility of CVD graphene is seriously limited by scattering from bilayer domains. Our results could be useful for guiding future optoelectronic applications of large-scale CVD graphene.
Cite this article：Yuanfang Yu, Zhenzhen Li, Wenhui Wang, Xitao Guo, Jie Jiang, Haiyan Nan and Zhenhua Ni. Investigation of multilayer domains in large-scale CVD monolayer graphene by optical imaging. Journal of Semiconductors, 2017, 38(3): 033003
Fig. 2. (a) Optical image of CVD graphene with multilayer domains. (b) 3D image of G-channel contrast value extracted from (a). (c) Histogram of optical contrast distribution. (d) Gaussian fitting for peaks of the contrast distribution, solid red lines are the fitting results.