Influence of interface dipole layers on the performance of graphene field effect transistors
Influence of interface dipole layers on the performance of graphene field effect transistors
复制标题
DOI：
10.1016/j.carbon.2019.06.038
复制
发表时间：
2019-07
期刊：
影响因子：
10.9
通讯作者：
N. Nagamura;H. Fukidome;K. Nagashio;K. Horiba;T. Ide;K. Funakubo;K. Tashima;A. Toriumi;M. Suemitsu;K. Horn;M. Oshima
中科院分区：
文献类型：
--
作者：
N. Nagamura;H. Fukidome;K. Nagashio;K. Horiba;T. Ide;K. Funakubo;K. Tashima;A. Toriumi;M. Suemitsu;K. Horn;M. Oshima
石墨烯在费米能级附近的线性色散产生了其独特的电子特性，如巨大的载流子迁移率，这引发了广泛的应用研究，如石墨烯场效应晶体管（gfet）。然而，与预期相比，gfet通常表现出的器件性能要差得多。这归因于石墨烯的电子特性对周围界面的强烈依赖。在这里，我们研究了石墨烯通道与SiO2之间的界面，并通过光电子能谱显微镜详细确定了界面上的能带对准过程。我们的研究结果表明，石墨烯的电子性质可以被亲水的sio2表面调制，而不是被疏水的sio2表面调制。通过结合光电子能谱与GFET输运特性表征，我们证明了反映sio2表面电化学性质的界面电偶极子的存在决定了GFET器件的性能。电阻对栅极电压的迟滞作为极性的函数归因于栅极电压对偶极层的反转。这些数据为GFET器件优化铺平了道路。
The linear band dispersion of graphene's bands near the Fermi level gives rise to its unique electronic properties, such as a giant carrier mobility, and this has triggered extensive research in applications, such as graphene field-effect transistors (GFETs). However, GFETs generally exhibit a device performance much inferior compared to the expected one. This has been attributed to a strong dependence of the electronic properties of graphene on the surrounding interfaces. Here we study the interface between a graphene channel and SiO2, and by means of photoelectron spectromicroscopy achieve a detailed determination of the course of band alignment at the interface. Our results show that the electronic properties of graphene are modulated by a hydrophilic SiO2surface, but not by a hydrophobic one. By combining photoelectron spectromicroscopy with GFET transport property characterization, we demonstrate that the presence of electrical dipoles in the interface, which reflects the SiO2surface electrochemistry, determines the GFET device performance. A hysteresis in the resistance vs. gate voltage as a function of polarity is ascribed to a reversal of the dipole layer by the gate voltage. These data pave the way for GFET device optimization.