Blends of conjugated and adhesive polymers for multifunctional organic thin-film transistors

Organic thin-film transistors (OTFTs) have attracted significant attention due to their large area compatibility, potential solution processability, and stretchability. In this work, we present a novel polymer blend that consists of a conjugated polymer (Poly(3-hexylthiophene-2,5-diyl), Poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene], or Poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno[3,2-b]thiophene)]) and an adhesive polymer (Poly[(3,4-dihydroxystyrene)-co-styrene]) as the active layer of OTFTs. The blend films possess both semiconductive and adhesive properties that can be utilized to enable 3D integration and minimize delamination. For a broad range of composition of the blended films, OTFTs maintain comparatively constant field-effect charge carrier mobility. Addition of a conjugated polymer helps improve adhesion strength of the bonded films until an optimal adhesion strength is achieved, up to 1.28 MPa. This strategy for polymer blends is an example of the potential for multifunctional OTFTs.