TY - JOUR
T1 - Synthesis of [7]phenacene incorporating tetradecyl chains in the axis positions and its application in field-effect transistors
AU - Okamoto, Hideki
AU - Hamao, Shino
AU - Kozasa, Keiko
AU - Wang, Yanan
AU - Kubozono, Yoshihiro
AU - Pan, Yong He
AU - Yen, Yu Hsiang
AU - Hoffmann, Germar
AU - Tani, Fumito
AU - Goto, Kenta
N1 - Funding Information:
This study was partly supported by Grants-in-Aid (26105004, 17K05976, 17K05500, 18K04940, 18K18736 and 19H02676) from MEXT, the JST-ACT-C project of the Japan Science and Technology Agency (No. JPMJCR 12YW), and the Program for Promoting the Enhancement of Research Universities from MEXT, Japan. Moreover, a part of this study (STM and STS studies) was supported by Grants (105-2112-M-007-022-MY3 and 106-2923-M-007-001-MY4) from the Ministry of Science and Technology (MOST) in Taiwan and by the Center for Quantum Technology, National Tsing Hua University, from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. Instrumental analyses of the novel compounds were supported by the Cooperative Research Program of the ?Network Joint Research Center for Materials and Devices? from MEXT, Japan. HO thanks Prof. Hiroko Yamada (NAIST) for HRMS measurement of (C14H29)2-[7]phenacene.
Publisher Copyright:
© The Royal Society of Chemistry 2020.
PY - 2020/6/14
Y1 - 2020/6/14
N2 - Field-effect transistors (FETs) were fabricated using a new type of phenacene molecule, 3,12-ditetradecyl[7]phenacene ((C14H29)2-[7]phenacene), and solid gate dielectrics or an electric double layer (EDL) capacitor with an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (bmim[PF6])). The new molecule, (C14H29)2-[7]phenacene, was efficiently synthesizedviathe Mallory photoreaction. Its crystal structure and electronic properties were determined, using X-ray diffraction, scanning tunneling microscopy/spectroscopy (STM and STS), absorption spectroscopy, and photoelectron yield spectroscopy, which showed a monoclinic crystal lattice (space groupP21(no. 4)) and an energy gap of ∼3.0 eV. The STM image clearly showed the molecular structure of (C14H29)2-[7]phenacene, as well as the closed molecular stacking, indicative of a strong fastener effect between alkyl chains. The X-ray diffraction pattern of thin films of (C14H29)2-[7]phenacene formed on a SiO2/Si substrate suggested that the molecule stood on the surface with an inclined angle of 30° with respect to the normal axis of the surface. The FET properties were recorded in two-terminal measurement mode, showing p-channel normally-off characteristics. The averaged values of field-effect mobility,μ, were 1.6(3) cm2V−1s−1for a (C14H29)2-[7]phenacene thin-film FET with a SiO2gate dielectric and 6(4) × 10−1cm2V−1s−1for a (C14H29)2-[7]phenacene thin-film EDL FET with bmim[PF6]. Thus, higher FET performance was obtained with an FET using a thin film of (C14H29)2-[7]phenacene compared to parent [7]phenacene. This study could pioneer an avenue for the realization of high-performance FETs through the addition of alkyl chains to phenacene molecules.
AB - Field-effect transistors (FETs) were fabricated using a new type of phenacene molecule, 3,12-ditetradecyl[7]phenacene ((C14H29)2-[7]phenacene), and solid gate dielectrics or an electric double layer (EDL) capacitor with an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (bmim[PF6])). The new molecule, (C14H29)2-[7]phenacene, was efficiently synthesizedviathe Mallory photoreaction. Its crystal structure and electronic properties were determined, using X-ray diffraction, scanning tunneling microscopy/spectroscopy (STM and STS), absorption spectroscopy, and photoelectron yield spectroscopy, which showed a monoclinic crystal lattice (space groupP21(no. 4)) and an energy gap of ∼3.0 eV. The STM image clearly showed the molecular structure of (C14H29)2-[7]phenacene, as well as the closed molecular stacking, indicative of a strong fastener effect between alkyl chains. The X-ray diffraction pattern of thin films of (C14H29)2-[7]phenacene formed on a SiO2/Si substrate suggested that the molecule stood on the surface with an inclined angle of 30° with respect to the normal axis of the surface. The FET properties were recorded in two-terminal measurement mode, showing p-channel normally-off characteristics. The averaged values of field-effect mobility,μ, were 1.6(3) cm2V−1s−1for a (C14H29)2-[7]phenacene thin-film FET with a SiO2gate dielectric and 6(4) × 10−1cm2V−1s−1for a (C14H29)2-[7]phenacene thin-film EDL FET with bmim[PF6]. Thus, higher FET performance was obtained with an FET using a thin film of (C14H29)2-[7]phenacene compared to parent [7]phenacene. This study could pioneer an avenue for the realization of high-performance FETs through the addition of alkyl chains to phenacene molecules.
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U2 - 10.1039/d0tc00272k
DO - 10.1039/d0tc00272k
M3 - Article
AN - SCOPUS:85086314262
VL - 8
SP - 7422
EP - 7435
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 22
ER -