Mahdaoui Dorra, Hirata Chika, Nagaoka Kahori, Miyazawa Kun'ichi, Fujii Kazuko, Ando Toshihiro, Abderrabba Manef, Ito Osamu, Yagyu Shinjiro, Liu Yubin, Nakajima Yoshiyuki, Tsukagoshi Kazuhito, Wakahara Takatsugu
Electronic Functional Macromolecules Group, Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan.
Laboratory of Materials, Molecules and Applications, Preparatory Institute for Scientific and Technical Studies, University of Carthage, B.P. 51, La Marsa 2075, Tunisia.
Nanomaterials (Basel). 2023 Sep 1;13(17):2469. doi: 10.3390/nano13172469.
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 C/ferrocene (C/Fc). When heated to 150 °C, the initially ambipolar monoclinic C/Fc nanosheet-based field-effect transistors (FETs) were transformed into n-type face-centered cubic (fcc) C 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 C/Fc nanosheet-based FETs were also found to be much more thermally stable than the previously reported C/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.
有机共晶体由非共价分子间相互作用组装而成，因其卓越的化学物理性质和实际应用而备受关注。一个显著特征，即共晶体内的电荷转移（CT）相互作用，不仅有助于形成有序的超分子网络，还赋予它们理想的半导体特性。在此，我们展示了由C/二茂铁（C/Fc）单晶组成的纳米片所呈现的有趣的双极性CT特性。当加热到150°C时，最初基于双极性单斜C/Fc纳米片的场效应晶体管（FET）由于二茂铁的消除而转变为基于n型面心立方（fcc）C纳米片的FET。这种晶体结构的热诱导变化伴随着器件半导体行为的不可逆切换；因此，器件从双极性转变为单极性。重要的是，还发现基于C/Fc纳米片的FET比先前报道的基于C/Fc纳米片的FET具有更高的热稳定性。此外，我们进行了可见/近红外漫反射和光发射产率光谱分析，以研究二茂铁在调节CT特性中所起的关键作用。这项研究为这些纳米片结构的整体功能提供了有价值的见解。
