Facile Fabrication and Characterization of Oriented and Multilayer Thin Films of Solution Processable Conjugated Polymer

Fabrication of multilayer thin films of solution-processable organic semiconductors has great potential in organic electronics, but adopting existing thin-film techniques to attain this is highly cumbersome. Herein, a unique unidirectional floating film transfer method has been utilized, which allows the facile fabrication of large area and oriented thin films of conjugated polymers. This method has successfully fabricated and characterized multilayer and oriented thin films of regioregular poly(3-hexylthiophene) without having any adverse effect on the underlying layers. Optical characterizations reveal that fabricated thin films are anisotropic with a dichroic ratio of 2.2 having a single layer thickness of 14.5 nm. X-ray diffraction results demonstrate uniformity in the crystallinity of the multilayered thin film with comparable crystallite size and interplanar spacing with purely edge-on molecular orientation. The organic field effect transistor fabricates using multilayer thin films and also exhibits a uniform and saturated charge carrier mobility of about 0.1 cm2 V-1 s-1. Polymer thin films play a pivotal role in multilayer fabrication by serving as versatile, customizable building blocks that enable precise control over material properties, thickness, and functionality to engineer complex composite structures. Unidirectional floating film transfer method, where the thin films can be independently cast without damaging the underlying layer, is developed.image (c) 2023 WILEY-VCH GmbH