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arXiv · 1907.03310

Influence of interface dipole layers on the performance of graphene field effect transistors

Naoka Nagamura·Hirokazu Fukidome·Kosuke Nagashio·Koji Horiba·Takayuki Ide·Kazutoshi Funakubo·Keiichiro Tashima·Akira Toriumi·Maki Suemitsu·Karsten Horn·Masaharu Oshima
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Abstract

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 SiO$_{2}$, 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 SiO$_{2}$ surface, 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 SiO$_{2}$ surface 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.

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Naoka Nagamura, Hirokazu Fukidome, Kosuke Nagashio, Koji Horiba, Takayuki Ide, Kazutoshi Funakubo, Keiichiro Tashima, Akira Toriumi, Maki Suemitsu, Karsten Horn, Masaharu Oshima. 2019-07-07. Influence of interface dipole layers on the performance of graphene field effect transistors. https://doi.org/10.1016/j.carbon.2019.06.038

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