Thermally and Mechanically Stable Polyimides as Flexible Substrates for Organic Field-Effect Transistors
Journal
ACS Applied Polymer Materials
Journal Volume
2
Journal Issue
8
Pages
3422-3432
Date Issued
2020
Author(s)
Abstract
Highly thermal-mechanical stable polymers have attracted extensive research interest as substrates for flexible or wearable electronic devices, such as polyimides (PIs). Here, we report a class of PIs as substrates for flexible organic field-effect transistors (OFETs), prepared by the polycondensation of pyromellitic dianhydride (PMDA) or 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride (BPDA) with three kinds of heterocyclic diamines, including 2,6-diaminothianthrene (SSDA), 2,6-diaminophenoxathiin (SODA), and 2,6-diaminodibenzo-p-dioxin (OODA). Flexible and tough PI films were obtained with a very low coefficient of thermal expansion (CTE) down to 7.3 ppm K-1. Furthermore, the copolymers of PI(OODA-PmBn) prepared from PMDA and BPDA with OODA could exhibit an extremely low CTE of 5.5 ppm K-1 (PI(OODA-P5B5)) without an observed Tg up to 400 °C, which was attributed to the suitable polymer chain rigidity and packing resulting in better in-plane orientation. Finally, this superheat-resistant PI(OODA-P5B5) was applied as the substrate in flexible OFETs, showing compatible and stable device performance even after being baked at 200 °C for 2 h or bended for 1000 cycles. These results indicate that the designed super-thermal-mechanically stable polyimides have potential applications as substrates for flexible electronics. Copyright © 2020 American Chemical Society.
Subjects
field-effect transistor; heterocyclic ring; polyimide; substrate; thermal-mechanical resistance
Other Subjects
Flexible electronics; Organic field effect transistors; Polyimides; Thermal expansion; Device performance; Electronic device; Flexible substrate; In-plane orientation; Low coefficient of thermal expansions; Mechanically stable; Pyromellitic dianhydride; Research interests; Substrates
Type
journal article