Graphene/MoS_2异质结的能带结构研究

Study on band structure of Graphene/MoS_2 heterostructures

石墨烯具有优异的光学和电学性质,同时其与其它二维材料形成的异质结在改善接触,能带调控等方面展现出了应用前景。然而,该类异质结结构中能带特性一直缺乏直接的研究分析,本文中以Graphene/MoS_2异质结为研究对象,通过开尔文探针力显微镜原位分析了其能带结构。结果发现:在二维Graphene/MoS_2异质结中,石墨烯的功函数比硫化钼的功函数小,Graphene/MoS_2异质结具有有利于接触的能带结构,可以解释在类似的二维材料异质结电输运实验中,观察到较低的肖特基势垒;退火后,Graphene/MoS_2异质结之间的肖特基势垒高度进一步减小。本课题组的研究显示出石墨烯在改善二维材料相关器件电学性能方面有很大的潜力。

Graphene has shown great potential application in broad fields due to its optical and electrical properties.Especially,it exhibits excellent performance in the electrical contact improving and band structure engineering when the graphene is formed heterojunction with other two-dimensional materials.However,the band structure characteristics in the graphene based heterojunctions structure have always been lack of direct evidence.Here the Graphene/MoS2 heterostructure was investigated and its band structure was in-situ analyzed by Kelvin probe force microscop(KPFM).It is found that,the work function of graphene is smaller than that of the MoS2 in the heterostructure,which benefits for the decrease of Schottky barrier.After thermal treatment process,the Schottky barrier height between the graphene and MoS2 is further reduced.Our research shows that the graphene has great potential to improve the electrical performances of two-dimensional material related devices.