Ambipolar to Unipolar Conversion in C<sub>70</sub>/Ferrocene Nanosheet Field-Effect Transistors
Dorra Mahdaoui,
Chika Hirata,
Kahori Nagaoka,
Kun’ichi Miyazawa,
Kazuko Fujii,
Toshihiro Ando,
Manef Abderrabba,
Osamu Ito,
Shinjiro Yagyu,
Yubin Liu,
Yoshiyuki Nakajima,
Kazuhito Tsukagoshi,
Takatsugu Wakahara
Affiliations
Dorra Mahdaoui
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Chika Hirata
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Kahori Nagaoka
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Kun’ichi Miyazawa
Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
Kazuko Fujii
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Toshihiro Ando
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Manef Abderrabba
Laboratory of Materials, Molecules and Applications, Preparatory Institute for Scientific and Technical Studies, University of Carthage, B.P. 51, La Marsa 2075, Tunisia
Osamu Ito
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Shinjiro Yagyu
Nano Electronics Device Materials Group, Research Center for Electronic and Optical Materials, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Yubin Liu
RIKEN KEIKI Co., Ltd., 2-7-6, Azusawa, Itabashi-ku, Tokyo 174-8744, Japan
Yoshiyuki Nakajima
RIKEN KEIKI Co., Ltd., 2-7-6, Azusawa, Itabashi-ku, Tokyo 174-8744, Japan
Kazuhito Tsukagoshi
International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Takatsugu Wakahara
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
Organic cocrystals, which are assembled by noncovalent intermolecular interactions, have garnered intense interest due to their remarkable chemicophysical properties and practical applications. One notable feature, namely, the charge transfer (CT) interactions within the cocrystals, not only facilitates the formation of an ordered supramolecular network but also endows them with desirable semiconductor characteristics. Here, we present the intriguing ambipolar CT properties exhibited by nanosheets composed of single cocrystals of C70/ferrocene (C70/Fc). When heated to 150 °C, the initially ambipolar monoclinic C70/Fc nanosheet-based field-effect transistors (FETs) were transformed into n-type face-centered cubic (fcc) C70 nanosheet-based FETs owing to the elimination of Fc. This thermally induced alteration in the crystal structure was accompanied by an irreversible switching of the semiconducting behavior of the device; thus, the device transitions from ambipolar to unipolar. Importantly, the C70/Fc nanosheet-based FETs were also found to be much more thermally stable than the previously reported C60/Fc nanosheet-based FETs. Furthermore, we conducted visible/near-infrared diffuse reflectance and photoemission yield spectroscopies to investigate the crucial role played by Fc in modulating the CT characteristics. This study provides valuable insights into the overall functionality of these nanosheet structures.
