Development of acenedichalchogenophenedione-based organic semiconductors for near-infrared-active organic photodetectors

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15646
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Tohoku University
• Principal Investigator: Kawabata Kohsuke 東北大学, 理学研究科, 助教 (10710212)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 有機半導体 / 近赤外光吸収 / 有機電界効果トランジスタ / キノイド / ドナー-アクセプター / カルコゲン

Outline of Final Research Achievements

For the development of near-infrared (NIR) absorbing organic semiconductors for the application of NIR-active photodetectors, a series of new donor-acceptor-donor (D-A-D) organic semiconductors based on acenedichalcogenophenediones, which are fused-ring quinoidal structures, were synthesized and characterized. The D-A-D organic semiconductors synthesized in this study have an intense absorption band around 600-1000 nm in the solution state, whereas in the thin-film state, the absorption edges red-shift to 1000-1800 nm despite their neutral and closed shell electronic structures. Furthermore, organic field-effect transistor devices based the thin films exhibited air-stable ambipolar charge transport properties with hole and electron mobilities of up to 0.2 cm2/Vs. These results suggest that the acenedichalcogenophenediones are the promising building units for the development of NIR-absorbing organic semiconductors.

Free Research Field

材料化学

Academic Significance and Societal Importance of the Research Achievements

現在、近赤外光受光素子に用いられているシリコン半導体はその吸収波長域が1100 nmまでに限られていることから、さらに長波長域で利用可能な安価な半導体が求められている。近年、吸収波長域が1100 nmを超える近赤外吸収有機半導体が報告されているが、その多くは大気安定性が十分ではなかった。本研究で新たに開発した一連の有機半導体は、最長で1800 nmの吸収端を有するにも関わらず、大気下で良好な電荷輸送特性を示したことから、本分子設計は新規材料開発における重要な知見となりうる。