Stretchable Semiconducting Composite Films Fabricated Via Blending Polythiophene With An Elastomer Bearing Pendant Dopant

Conjugated polymers (CPs) are attractive candidates for the fabrication of next-generation soft and wearable electronics. Further ameliorating the electrical and mechanical properties of CPs is urgently required to meet the demand for the practical application. However, a dilemma lies in that the strategies aiming at achieving deformability typically result in the deterioration of charge transport and vice versa. In the present work, a protocol is proposed for fabricating stretchable semiconducting films by blending a model CP, poly(3-dodecylthiophene) (P3DDT), with a flexible copolymer poly(n-butyl acrylate)-co-poly(2-acrylamido-2-methylpropane sulfonic acid), in which the pendant sulfonic acid groups act as dopants. The strong interaction between P3DDT and the dopant has been confirmed, leading to enhanced conductive property, uniform distribution of P3DDT nanofibrils in the matrix, and improved interface between P3DDT and the matrix, As a result, the composite films with both improved electrical and mechanical properties are obtained, even though the amount of P3DDT in composite films is only 10 wt %. This work may provide a strategy for the design of cost-effective stretchable semiconducting devices.