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Controlling Ambipolar Charge Transport in Isoindigo-Based Conjugated P…

Year of publication
Title of paper
Controlling Ambipolar Charge Transport in Isoindigo-Based Conjugated Polymers by Altering Fluorine Substitution Position for High-Performance Organic Field-Effect Transistors
Author
[박태호교수 연구실]
Publication in journal
Advancec Functional Materials 29(10), p1805994, 2019
Publication date
20190307

[Abstract]

A molecular design strategy to achieve highly balanced ambipolar charge transport for donor–acceptor (D–A) isoindigo (IIG)‐based copolymer through systematic selection of fluorination positions is reported. To study fluorine substitution site effects on electronic and structural properties, two fluorinated IIG‐based copolymers (PIIG‐iFT2 and PIIG‐oFT2) are synthesized, which contain two fluorine atoms at the bithiophene (T2) inner and outer site and compare them with a nonfluorinated copolymer of IIG and T2 (PIIG‐T2) as the reference polymer. Fluorination at the outer site of T2 in PIIG‐oFT2 polymer effectively lowers molecular energy levels and increases molecular planarity more than fluorination at the T2 inner site. PIIG‐oFT2 organic field‐effect transistors show highly balanced ambipolar mobility, hole mobility (μh)/electron mobility (μe) = 1 by increasing electron mobility, whereas PIIG‐T2 (μh/μe = 9.0) and PIIG‐iFT2 (μh/μe = 2.4) exhibit unbalanced ambipolar transport. The ambipolar complementary‐like inverter is also demonstrated by simple one‐time coating of PIIG‐oFT2 with gain = 21.

 

DOI: 10.1002/adfm.201805994

LINK: https://onlinelibrary.wiley.com/doi/10.1002/adfm.201805994