Optical imaging and spectroscopy of atomically precise armchair graphene nanoribbons
S. Zhao, G. Borin Barin, T. Cao, J. Overbeck, R. Darawish, T. Lyu, S. Grant Drapcho, S. Wang, T. Dumslaff, A. Narita, M. Calame, K. Müllen, S. G. Louie, P. Ruffieux, R. Fasel, and F. Wang
Nano Letters (2020)
We report the optical imaging and absorption spectroscopy on atomically precise armchair graphene nanoribbons (GNRs) on insulating fused silica substrates. This is achieved by controlling light polarization on macroscopically aligned GNRs, which greatly enhances the sub-monolayer GNR optical contrast on the insulating substrates. We measured the linear absorption spectra of 7-armchair and 9-armchair GNRs in this study, and the experimental data agree qualitatively with ab inito calculation results. The polarization spectroscopy technique enables an unambiguous optical identification of GNR samples and provides a rapid tool to characterize the transferred film over large area.