2025-09-04 東京大学,横浜国立大学,東京理科大学,産業技術総合研究所,科学技術振興機構
アンバイポーラ（両極性）の分子半導体を用いることで、単一材料内において正孔と電子が異なる輸送異方性を示す有機電界効果トランジスタ（OFET）を実現
＜関連情報＞
- https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=28050
- https://www.issp.u-tokyo.ac.jp/news/wp-content/uploads/2025/09/0902_press_anistropy.pdf
- https://onlinelibrary.wiley.com/doi/10.1002/anie.202512609
両極性ニッケルジチオレン系半導体における顕著な正孔・電子輸送異方性 Distinct Hole and Electron Transport Anisotropy in Ambipolar Nickel Dithiolene-Based Semiconductor
Dr. Masatoshi Ito, Assoc. Prof. Tomoko Fujino, Dr. Toshiki Higashino, Assoc. Prof. Mafumi Hishida, Prof. Hatsumi Mori
Angewandte Chemie International Edition Published: 03 September 2025
DOI:https://doi.org/10.1002/anie.202512609
Abstract
Understanding anisotropic charge transport in molecular semiconductors is crucial for device optimization, yet its intricate dependence on orbital-specific intermolecular interactions and molecular packing remains a challenge, especially in ambipolar systems. In ambipolar semiconductors, where both holes and electrons participate in conduction, distinct molecular orbitals prompt a critical inquiry: can orbital variations result in coexisting yet distinct anisotropic transport properties within a single component? We confirm this possibility by demonstrating that the air-stable nickel dithiolene, Ni(4OPr), exhibits such behavior. Despite its herringbone stacking implying a two-dimensional electronic structure, Ni(4OPr) uniquely exhibits distinct intermolecular interactions for hole (HOMO-to-HOMO; HOMO = highest occupied molecular orbital) and electron (LUMO-to-LUMO; LUMO = lowest unoccupied molecular orbital) transport. Crucially, this leads to highly anisotropic hole transport pathways, while electron pathways are remarkably isotropic, demonstrating a stark contrast in their transport anisotropies. Leveraging the high crystallinity, grazing-incidence wide-angle X-ray scattering (GIWAXS) determined in-plane molecular orientation. This enabled experimental verification of distinct anisotropic hole and electron transport, directly governed by orbital-specific intermolecular interactions, in an ambipolar molecular semiconductor. Our findings, demonstrating coexisting yet distinct anisotropic transport properties for both carriers within a single component, significantly advance the understanding of ambipolar molecular semiconductors and broaden their scope for future device applications.
