A vertical silicon-graphene-germanium transistor.

ABSTRACT: Graphene-base transistors have been proposed for high-frequency applications because of the negligible base transit time induced by the atomic thickness of graphene. However, generally used tunnel emitters suffer from high emitter potential-barrier-height which limits the transistor performance towards terahertz operation. To overcome this issue, a graphene-base heterojunction transistor has been proposed theoretically where the graphene base is sandwiched by silicon layers. Here we demonstrate a vertical silicon-graphene-germanium transistor where a Schottky emitter constructed by single-crystal silicon and single-layer graphene is achieved. Such Schottky emitter shows a current of 692?A?cm^-2 and a capacitance of 41 nF cm^-2, and thus the alpha cut-off frequency of the transistor is expected to increase from about 1?MHz by using the previous tunnel emitters to above 1?GHz by using the current Schottky emitter. With further engineering, the semiconductor-graphene-semiconductor transistor is expected to be one of the most promising devices for ultra-high frequency operation.

SUBMITTER: Liu C 

PROVIDER: S-EPMC6814790 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature