Field-effect transistor

The disclosed field-effect transistor has a graphene channel, and does not exhibit ambipolar properties. Specifically, the field-effect transistor has a semi-conducting substrate; a channel including a graphene layer disposed on the aforementioned semiconductor substrate; a source electrode and drain electrode comprising a metal; and a gate electrode. The aforementioned channel and the aforementioned source and drain electrodes comprising a metal are connected via a semiconductor layer.