Graphene transfer in vacuum yielding a high quality graphene

The importance of proper graphene transfer process cannot be emphasized more because it is so closely related to the performance and stability of graphene devices. In this work, a new transfer method utilizing a voluntary bonding of a graphene film to a target substrate in vacuum is demonstrated. The problems originated from water and air molecules which prevent a robust bonding and degrade the electrical characteristics could be drastically alleviated. As a result, graphene field-effect transistors showed nearly symmetric Id-Vg characteristics with a minimal hysteresis and drastically improved device stability in air for more than a month could be obtained.