Regiochemistry-driven organic electrochemical transistor performance enhancement in ethylene glycol-functionalized polythiophenes

by R.K. Hallani, B.D. Paulsen, A.J. Petty, R. Sheelamanthula, M. Moser, K.J. Thorley, W. Sohn, R.B. Rashid, A. Savva, S. Moro, (…), S. Inal, G. Costantini, J. Rivnay, I. McCulloch
Year:2021 DOI: 10.1021/jacs.1c03516

Bibliography

Regiochemistry-driven organic electrochemical transistor performance enhancement in ethylene glycol-functionalized polythiophenes
R.K. Hallani, B.D. Paulsen, A.J. Petty, R. Sheelamanthula, M. Moser, K.J. Thorley, W. Sohn, R.B. Rashid, A. Savva, S. Moro, (…), S. Inal, G. Costantini, J. Rivnay, I. McCulloch
Journal of the American Chemical Society 143 (29), 11007-11018, 2021

Abstract

Novel p-type semiconducting polymers that can facilitate ion penetration, and operate in accumulation mode are much desired in bioelectronics. Glycol side chains have proven to be an efficient method to increase bulk electrochemical doping and optimize aqueous swelling. One early polymer which exemplifies these design approaches was p(g2T-TT), employing a bithiophene-co-thienothiophene backbone with glycol side chains in the 3,3′ positions of the bithiophene repeat unit. In this paper, the analogous regioisomeric polymer, namely pgBTTT, was synthesized by relocating the glycol side chains position on the bithiophene unit of p(g2T-TT) from the 3,3′ to the 4,4′ positions and compared with the original p(g2T-TT). By changing the regio-positioning of the side chains, the planarizing effects of the S–O interactions were redistributed along the backbone, and the influence on the polymer’s microstructure organization was investigated using grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements. The newly designed pgBTTT exhibited lower backbone disorder, closer π-stacking, and higher scattering intensity in both the in-plane and out-of-plane GIWAXS measurements. The effect of the improved planarity of pgBTTT manifested as higher hole mobility (μ) of 3.44 ± 0.13 cm2 V–1 s–1. Scanning tunneling microscopy (STM) was in agreement with the GIWAXS measurements and demonstrated, for the first time, that glycol side chains can also facilitate intermolecular interdigitation analogous to that of pBTTT. Electrochemical quartz crystal microbalance with dissipation of energy (eQCM-D) measurements revealed that pgBTTT maintains a more rigid structure than p(g2T-TT) during doping, minimizing molecular packing disruption and maintaining higher hole mobility in operation mode.

Keywords

Electrochemical doping Electrochemical quartz crystal microbalance Ethylene glycol Organic electrochemical transistors
KAUST

"KAUST shall be a beacon for peace, hope and reconciliation, and shall serve the people of the Kingdom and the world."

King Abdullah bin Abdulaziz Al Saud, 1924 – 2015

Contact Us

  • 4700 King Abdullah University of Science and Technology

    Thuwal 23955-6900, Kingdom of Saudi Arabia

Quick links

© King Abdullah University of Science and Technology. All rights reserved