Vinylene and benzo[ c][1,2,5]thiadiazole: effect of the π-spacer unit on the properties of bis(2-oxoindolin-3-ylidene)-benzodifuran-dione containing polymers for n-channel organic field-effect transistors

Thu Trang Do; Basanagouda B Patil; Samarendra P Singh; Soniya D Yambem; Krishna Feron; Kostya Ken Ostrikov; John M Bell; Prashant Sonar

doi:10.1039/c8ra08890j

Vinylene and benzo[ c][1,2,5]thiadiazole: effect of the π-spacer unit on the properties of bis(2-oxoindolin-3-ylidene)-benzodifuran-dione containing polymers for n-channel organic field-effect transistors

RSC Adv. 2018 Nov 20;8(68):38919-38928. doi: 10.1039/c8ra08890j. eCollection 2018 Nov 16.

Authors

Thu Trang Do¹, Basanagouda B Patil¹, Samarendra P Singh², Soniya D Yambem¹, Krishna Feron^{3

4}, Kostya Ken Ostrikov¹, John M Bell¹, Prashant Sonar¹

Affiliations

¹ School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT) 2 George Street Brisbane QLD-4001 Australia [email protected].
² Department of Physics, School of Natural Sciences, Shiv Nadar University (SNU) Gautam Buddha Nagar Uttar Pradesh India-201307.
³ CSIRO Energy Centre NSW-2304 Australia.
⁴ Centre for Organic Electronics, University of Newcastle Callaghan NSW 2308 Australia.

Abstract

Two polymers based on (3E,7E)-3,7-bis(2-oxoindolin-3-ylidene)benzo[1,2-b:4,5-b']difuran-2,6(3H,7H)-dione (BIBDF) coupled with (E)-2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) or dithienylbenzothiadiazole (TBT), namely PBIBDF-TVT and PBIBDF-TBT were synthesized via the Stille coupling reaction. The effect of benzothiadiazole or vinylene-π spacer of the copolymers on optical properties, energy levels, electronic device performance and microstructure were studied. It was found that PBIBDF-TBT based OFET devices, annealed at 180 °C, showed better performance with the highest electron mobility of 2.9 × 10^-2 cm² V s^-1 whereas PBIBDF-TVT polymer exhibited 5.0 × 10^-4 cm² V s^-1. The two orders of magnitude higher electron mobility of PBIBDF-TBT over PBIBDT-TVT is a clear indicator of the better charge transport ability of this polymer semiconductor arising from its higher crystallinity and better donor-acceptor interaction.