Thiazole Imide-Based All-Acceptor Homopolymer: Achieving High-Performance Unipolar Electron Transport in Organic Thin-Film Transistors

Yongqiang Shi; Han Guo; Minchao Qin; Jiuyang Zhao; Yuxi Wang; Hang Wang; Yulun Wang; Antonio Facchetti; Xinhui Lu; Xugang Guo

doi:10.1002/adma.201705745

Thiazole Imide-Based All-Acceptor Homopolymer: Achieving High-Performance Unipolar Electron Transport in Organic Thin-Film Transistors

Adv Mater. 2018 Mar;30(10). doi: 10.1002/adma.201705745. Epub 2018 Jan 16.

Authors

Affiliations

¹ Department of Materials Science and Engineering and The Shenzhen Key Laboratory for Printed Organic Electronics, South University of Science and Technology of China (SUSTC), No. 1088, Xueyuan Road, Shenzhen, Guangdong, 518055, China.
² Department of Physics, The Chinese University of Hong Kong, New Territories, 999077, Hong Kong.
³ Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, IL, 60208, USA.

PMID: 29337389
DOI: 10.1002/adma.201705745

Abstract

High-performance unipolar n-type polymer semiconductors are critical for advancing the field of organic electronics, which relies on the design and synthesis of new electron-deficient building blocks with good solubilizing capability, favorable geometry, and optimized electrical properties. Herein, two novel imide-functionalized thiazoles, 5,5'-bithiazole-4,4'-dicarboxyimide (BTzI) and 2,2'-bithiazolothienyl-4,4',10,10'-tetracarboxydiimide (DTzTI), are successfully synthesized. Single crystal analysis and physicochemical study reveal that DTzTI is an excellent building block for constructing all-acceptor homopolymers, and the resulting polymer poly(2,2'-bithiazolothienyl-4,4',10,10'-tetracarboxydiimide) (PDTzTI) exhibits unipolar n-type transport with a remarkable electron mobility (μ_e ) of 1.61 cm² V^-1 s^-1 , low off-currents (I_off ) of 10^-10 -10^-11 A, and substantial current on/off ratios (I_on /I_off ) of 10⁷ -10⁸ in organic thin-film transistors. The all-acceptor homopolymer shows distinctive advantages over prevailing n-type donor-acceptor copolymers, which suffer from ambipolar transport with high I_off s > 10^-8 A and small I_on /I_off s < 10⁵ . The results demonstrate that the all-acceptor approach is superior to the donor-acceptor one, which results in unipolar electron transport with more ideal transistor performance characteristics.

Keywords: all-acceptor homopolymers; imide-functionalized thiazoles; n-type polymer semiconductors; organic thin-film transistors; unipolar transport.