▎ 摘　　要

Graphene is a flat monolayer of carbon atoms with a two-dimensional honeycomb lattice, and many layers of it constitute graphite. Single-layer graphene has been discovered recently and found to have excellent electrical and thermal properties, making it a promising material for future electronics. We performed first-principle calculations which do not use empirical parameters and elucidated the electronic states of graphene under an electric field. We also clarified the electronic states of graphene at the interface with an electrode. We further simulated electron transport in graphene and found that it can be a channel material for high-speed and high-frequency transistors with a performance better than InP-HEMT. Moreover, we succeeded in synthesizing graphene and a composite structure consisting of graphene and vertically aligned carbon nanotubes on a substrate. In this paper, we describe our theoretical and experimental approaches aimed at future applications of graphene.