▎ 摘　　要

Graphene nanoribbons (GNRs) were successfully synthesized by the longitudinal unzipping of a single-walled carbon nanotube (SWNT). In this process, a short-duration sonication was performed to unzip the SWNT. The obtained results clearly show that the synthesized GNR is semiconducting. Furthermore, it is also confirmed by Raman spectroscopy that the time variation of the samples during the unzipping process has two types of reaction, namely, fast and slow. Furthermore, the obtained results confirm that the narrower SWNT should be unzipped quickly, whereas the wider SWNT should be unzipped slowly. (C) 2017 The Japan Society of Applied Physics