Development of quinoidal molecules with tuned biradical character and application to photodiode and thermoelectric devices

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K21224
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 35:Polymers, organic materials, and related fields
• Research Institution: Osaka University
• Principal Investigator: IE YUTAKA 大阪大学, 産業科学研究所, 教授 (80362622)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: キノイド / 有機半導体 / 電子輸送材料 / 光ダイオード / 熱電変換

Outline of Final Research Achievements

Elucidating the nature of electronic structures in pi-extended quinoids is of considerable importance. In this study, we utilized the aromatic stabilization of the quinoidal form by introducing benzene-annelated isothianaphthene structures to shed light on the problem related to the development of long quinoidal systems with controlled quinoidal/aromatic contributions and stabilities. The electronic structures are controlled precisely by the number and position of benzene-annelations. These quinoidal pentathiophenes function as organic semiconductors in transistor and near infrared phototransistor devices. As a result, the combination of quinoidal structures with cross-conjugated units constitutes a novel approach to modulate the electronic properties of pi-extended quinoids.

Free Research Field

有機機能化学

Academic Significance and Societal Importance of the Research Achievements

キノイド構造分子は基底状態においてキノイドとビラジカルの共鳴構造であり、鎖長が伸長するにつれてビラジカル性の寄与が大きくなる。本研究では、ビラジカル性を精密に調節した長鎖キノイド構造オリゴチオフェンを系統的に創出し、その特異な基礎物性と半導体材料としての機能開拓に成功した。得られた知見は、近赤外光やビラジカル性を利用した新機軸の有機エレクトロニクス材料の開発に活かせると期待される。