Side-illuminated tip-enhanced Raman study of edge phonon in graphene at the electrical breakdown limit

摘要

Nanoscale integration of graphene into a circuit requires a stable performance under high current density. However, the effects of the current density that approach the electronic breakdown limit of graphene are not well understood. We explored the effects of a high current density, close to the electronic breakdown limit of 10A/cm(～3.0 × 10~8A/cm~2), on graphene, using tip-enhanced Raman scattering. The results showed that the high current density induces Raman bands at 1456 and 1530 cm~(-1), which were assigned to edge-phonon modes originating from zigzag and armchair edges. This led us to conclude that C-C bonds are cleaved due to the high current density, leaving edge structures behind, which were detected through the observation of localized phonons.