Band-gap generation by applying an effective electric field using ionic-liquid gate and nanodevice fabrication

2015 Fiscal Year Final Research Report

• Project/Area Number: 24310105
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Microdevices/Nanodevices
• Research Institution: Tokyo University of Agriculture and Technology (2014-2015); Osaka University (2012-2013)
• Principal Investigator: Maehashi Kenzo 東京農工大学, 工学(系)研究科(研究院), 教授 (40229323)
• Co-Investigator(Kenkyū-buntansha): OHNO Yasuhide 大阪大学, 産業科学研究所, 助教 (90362623)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: グラフェン / 電界効果トランジスタ / イオン液体 / ラマン散乱分光 / 直接成長

Outline of Final Research Achievements

Ionic liquid-gated graphene field-effect-transistors were fabricated to generate a band gap in bilayer graphene by applying an effective electric field. From measurements of electrical characteristics as a function of temperature, a band gap of 235 meV was created in bilayer graphene. Electronic states and phonon energies in bilayer graphene were also investigated by electrical and optical measurements under an external electric field, which was controlled by applying bias voltages to a bottom gate and a transparent ionic liquid side gate in a field-effect transistor. The symmetric and antisymmetric optical phonons were visible in the Raman scattering spectra. Moreover, a simple method of directly synthesizing graphene on dielectric surfaces was demonstrated using simple annealing or laser irradiation without a carbon source gas. Gaphene field-effect-transistors were fabricated using these methods.

Free Research Field

半導体物性