Mechanical, Morphological, and Charge Transport Properties of NDI Polymers with Variable Built-in Π-Conjugation Lengths Probed by Simulation and Experiment
Journal article, 2024

Mechanically deformable polymeric semiconductors are a key material for fabricating flexible organic thin-film transistors (FOTFTs)-the building block of electronic circuits and wearable electronic devices. However, for many pi-conjugated polymers achieving mechanical deformability and efficient charge transport remains challenging. Here the effects of polymer backbone bending stiffness and film microstructure on mechanical flexibility and charge transport are investigated via experimental and computational methods for a series of electron-transporting naphthalene diimide (NDI) polymers having differing extents of pi-conjugation. The results show that replacing increasing amounts of the pi-conjugated comonomer dithienylvinylene (TVT) with the pi-nonconjugated comonomer dithienylethane (TET) in the backbone of the fully pi-conjugated polymeric semiconductor, PNDI-TVT100 (yielding polymeric series PNDI-TVTx, 100 >= x >= 0), lowers backbone rigidity, degree of texturing, and pi-pi stacking interactions between NDI moieties. Importantly, this comonomer substitution increases the mechanical robustness of PNDI-TVTx while retaining efficient charge transport. Thus, reducing the TVT content of PNDI-TVTx suppresses film crack formation and dramatically stabilizes the field-effect electron mobility upon bending (e.g., 2 mm over 2000 bending cycles). This work provides a route to tune pi-pi stacking in pi-conjugated polymers while simultaneously promoting mechanical flexibility and retaining good carrier mobility in FOTFTs.

flexible organic thin-film transistors

pi-conjugated

pi-pi stacking

de-conjugation

molecular dynamics simulation

Author

Dan Zhao

City University of Hong Kong

Northwestern Univ, Dept Chem, 2145 Sheridan Rd

Northwestern Univ, Mat Res Ctr, 2145 Sheridan Rd

University of Electronic Science and Technology of China

Donghyun Kim

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Sarbani Ghosh

Birla Institute of Technology and Science Pilani

Gang Wang

Northwestern Univ, Mat Res Ctr, 2145 Sheridan Rd

Northwestern Univ, Dept Chem, 2145 Sheridan Rd

Wei Huang

University of Electronic Science and Technology of China

Northwestern Univ, Mat Res Ctr, 2145 Sheridan Rd

Northwestern Univ, Dept Chem, 2145 Sheridan Rd

Zonglong Zhu

City University of Hong Kong

Tobin J. Marks

Northwestern Univ, Dept Chem, 2145 Sheridan Rd

Northwestern Univ, Mat Res Ctr, 2145 Sheridan Rd

Igor Zozoulenko

Linköping University

Antonio Facchetti

Georgia Institute of Technology

Northwestern Univ, Dept Chem, 2145 Sheridan Rd

Northwestern Univ, Mat Res Ctr, 2145 Sheridan Rd

Advanced Functional Materials

1616-301X (ISSN) 16163028 (eISSN)

Vol. 34 4 2310071

Subject Categories

Polymer Technologies

Materials Chemistry

Other Chemical Engineering

DOI

10.1002/adfm.202310071

More information

Latest update

2/20/2024