Abstract: Graphene-based field-effect transistors (FETs) were fabricated by electron beam lithography and lift-off process and the photoresponse in the transistor was investigated. Significant photocurrents can be detected when the channel graphene near the metal contact is illuminated by a laser spot (λ = 633 nm). Both the magnitude and direction of the photocurrent can be effectively modulated by the back-gate voltage. In addition, the photocurrent will saturate by increasing the gate voltage. A maximum responsivity of 46.5 μA/W is achieved, which can be contributed to develop the novel graphene-based photodetectors.

Key words: graphene field-effect transistors, photoresponse, back-gate modulation

摘要： 采用电子束曝光和剥离工艺制备石墨烯场效应晶体管, 并研究其光电响应特性。结果表明, 当激光光斑(波长为633 nm)照射在金属电极边缘的石墨烯沟道时, 可测得明显的光电流。背栅电压能够有效调制光电响应, 可以改变光电流的大小和方向。在背栅调控下, 光电流出现饱和现象, 石墨烯晶体管的光响应度最大达到46.5 μA /W，可用于构建基于石墨烯的新型光探测器。

关键词: 石墨烯场效应晶体管, 光电响应, 背栅调制