(692h) Effects of Deposition Methods and Solution Treatment on P3HT-Based Organic Field-Effect Transistors

The thin-film deposition of conjugated polymers can be controlled to improve device performance. The aggregation and crystallization of poly(3-hexylthiophene) (P3HT), a representative active layer material used for organic field-effect transistor (OFET) applications, is known to be improved by solution treatment. This investigation combines various deposition methods and solution treatment to explore how they affect the film structure and device performance. The study presents a new deposition method, namely vibration-assisted convective deposition, and compares the impact of it on poly(3-hexylthiophene) (P3HT) device performance vs. steady convective deposition, blade coating and spin coating. The UV-vis results show that convective deposition, especially assisted with vibration, leads to greater intrachain interaction, larger conjugation length, and better planarization of the polymer backbone. When a solution treatment such as sonication and aging is applied, P3HT films show J-like aggregation and (h11) series can be observed from GIWAXS patterns, which suggests 3D crystalline order. The high crystallinity and outstanding charge mobility can be attained, providing added insight into the structure-property-processing relationships.