采用化学气相沉积法(CVD)制备单层石墨烯,将其转移到300nm厚的SiO_2/Si衬底上.通过真空蒸镀法在石墨烯表面沉积Au电极,获得SiO_2/Si背栅石墨烯场效应晶体管,对其进行低温导电特性的测试.结果表明,背栅石墨烯场效应晶体管呈双极导电性,并表现出P型导电特性.室温下器件的电子迁移率为3478cm~2/V.s,开关比(on/off)为1.88.在低温下器件的电子迁移率降至2913cm~2/V.s,开关比上升到2.53,狄拉克点左移,P型掺杂效应减弱,温度对器件起到调制作用. Single-layer graphene was prepared by chemical vapor deposition (CVD) and transferred onto a 300nm-thick SiO 2 / Si substrate.The Au electrode was deposited on the surface of graphene by vacuum deposition to obtain a SiO 2 / Si back gate graphene field The results show that the gate-back graphene FETs have bipolar conductivity and exhibit P-type conductivity.The electron mobility of the device at room temperature is 3478cm 2 / Vs, The on / off ratio is 1.88. At low temperatures, the electron mobility of the device drops to 2913cm 2 / Vs, the switching ratio increases to 2.53, the Dirac point shifts to the left, the P-type doping effect decreases, Modulation effect.