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 2310071Subject Categories
Polymer Technologies
Materials Chemistry
Other Chemical Engineering
DOI
10.1002/adfm.202310071