Active control of opto-electronic properties of single conjugated polymer chains by control of their conformation

2018 Fiscal Year Final Research Report

• Project/Area Number: 26287097
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Biological physics/Chemical physics/Soft matter physics
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: VACHA Martin 東京工業大学, 物質理工学院, 教授 (50361746)
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: 1分子科学 / 共役系高分子

Outline of Final Research Achievements

In the field of polymer nanoscience, the relationship between conformation of a conjugated polymer chain and its optical and electrical properties is an important problem both fundamentally and in view of potential applications. Here, we attempted to actively and precisely control the conformation of a single conjugated polymer chain and study its spectroscopic properties and opto-electronic functionality in relation to its conformation. The conformation was controlled by the polymer chain topology resulting from its chemical composition, by incorporation of individual chains into cylinders of phase-separated block copolymers, and by polarity of the surrounding matrix. Using such conformation control, we measured single conjugated polymer chains fluorescence and electroluminescence, and analyzed their photophysical properties in terms of molecular aggregate and charge transfer states, as well as their opto-electronic properties in terms of electroluminescence dynamics.

Free Research Field

有機材料ナノスケール特性

Academic Significance and Societal Importance of the Research Achievements

本研究成果の主な学術的意義として、共役系高分子ポリフルオレンの緑色発光帯、いわゆるg-bandの原因の解明が挙げられる。ポリフルオレンを用いた有機ELデバイスの色純度や効率の低下を起すg-bandは今まで多く研究され、原因としてはポリフルオレンの酸化が主に挙げられてきた。本研究では、ポリフルオレンの酸化がg-bandの出現に与える影響は小さく、電荷移動凝集体およびH-会合体の2種類の会合状態がg-bandの原因になっていることを明らかにした。この結果は高分子のナノ科学の発展、または共役系高分子を用いた光電デバイスの開発に大きく影響することが期待できる。