Optical Imaging and Spectroscopy of Atomically Precise Armchair Graphene Nanoribbons
Sihan Zhao, Gabriela Borin Barin, Ting Cao, Jan Overbeck, Rimah Darawish, Tairu Lyu, Steve Drapcho, Sheng Wang, Tim Dumslaff, Akimitsu Narita, Michel Calame, Kläus Müllen, Steven G. Louie, Pascal Ruffieux, Román Fasel, Feng Wang
Abstract
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 optical contrast of the submonolayer GNRs on the insulating substrates. We measure 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 GNRs and provides a rapid tool to characterize the transferred film over a large area.