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CC BY-NC-ND 4.0 · Organic Materials 2021; 3(04): 469-476
DOI: 10.1055/a-1639-2383
Organic Materials in Electronics
Original Article

Incorporating Cyano Groups to a Conjugated Polymer Based on Double B←N-Bridged Bipyridine Units for Unipolar n-Type Organic Field-Effect Transistors

Xu Cao
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. of China
b   University of Science and Technology of China, Hefei, 230023, P. R. of China
$   These authors contributed equally to this work.
,
Yang Min
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. of China
c   University of Chinese Academy of Sciences, Beijing, 100049, P. R. of China
$   These authors contributed equally to this work.
,
Hongkun Tian
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. of China
,
Jun Liu 
a   State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. of China
b   University of Science and Technology of China, Hefei, 230023, P. R. of China
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Abstract

The development of n-type semiconductors lags far behind that of their p-type counterparts, demonstrating the exploration of exclusive n-type π-conjugated polymers is significant. The double B←N-bridged bipyridine (BNBP)-based polymers P-BNBP-TVT containing (E)-1,2-di(thiophen-2-yl)ethene (TVT) previously reported exhibits ambipolar character because of the electron-rich nature. Herein, we incorporated strong electron-withdrawing cyano groups into the 3,3′-positions of the TVT moiety to a copolymer P-BNBP-2CNTVT to develop n-type π-conjugated polymers. The LUMO/HOMO energy levels of P-BNBP-2CNTVT are −3.80/−5.95 eV, respectively, which are ~0.4 eV lower than that of P-BNBP-TVT without cyano groups. Unsurprisingly, compared with ambipolar P-BNBP-TVT, the organic field-effect transistors (OFETs) based on P-BNBP-2CNTVT showed unipolar n-type characteristics with an electron mobility of 0.026 cm2 · V−1 · s−1 and a lower threshold voltage of ~25 V as well as high I on/I off of ~105. This study demonstrates that organoboron π-conjugated polymers could be regarded as a tool for constructing exclusive n-type semiconducting polymers used in OFETs.

Key words

π-conjugated polymers - cyano-functionalization - organic field-effect transistors - electron transports - n-type polymer semiconductors

Supporting Information



Publication History

Received: 24 July 2021

Accepted: 02 September 2021

Accepted Manuscript online:
07 September 2021

Article published online:
15 October 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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