AI Article Synopsis
- Graphene-based materials show high carrier mobility, making them promising for integrated electronics, but their lack of a bandgap complicates the development of devices like transistors.
- Researchers have successfully induced an insulating state in bilayer graphene using a double-gate configuration, allowing them to control conductivity more effectively.
- This insulating state is likely due to the predicted opening of a bandgap between the valence and conduction bands, as indicated by resistance changes in response to temperature and electric field.
Article Abstract
The potential of graphene-based materials consisting of one or a few layers of graphite for integrated electronics originates from the large room-temperature carrier mobility in these systems (approximately 10,000 cm2 V(-1) s(-1)). However, the realization of electronic devices such as field-effect transistors will require controlling and even switching off the electrical conductivity by means of gate electrodes, which is made difficult by the absence of a bandgap in the intrinsic material. Here, we demonstrate the controlled induction of an insulating state--with large suppression of the conductivity--in bilayer graphene, by using a double-gate device configuration that enables an electric field to be applied perpendicular to the plane. The dependence of the resistance on temperature and electric field, and the absence of any effect in a single-layer device, strongly suggest that the gate-induced insulating state originates from the recently predicted opening of a bandgap between valence and conduction bands.
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