Highly Oriented and Ordered Water-Soluble Semiconducting Polymers in a DNA Matrix

Abstract

We fabricate organic field effect transistor (OFET) devices based on highly aligned aggregates of the conjugated polymer, poly[3-(potassium-7-hexanoate)-thiophene-2,5-diyl] (P3PHT), using self-organized DNA as a matrix. P3PHT is a water-soluble conjugated semiconducting polymer, which can be well-mixed with DNA to afford a P3PHT/DNA blend that can be effectively aligned by a simple shearing method. The charge carrier mobility of P3PHT is correlated with its orientation, which is related to inter- and/or intramolecular charge transport: mobility of the P3PHT/DNA blend along the pi-conjugation direction is 3 orders of magnitude higher compared to the case of neat P3PHT owing to the versatility of DNA as a template and charge injection layer. Additionally, the specific chemical interactions and physical electrostatic binding affinities between DNA and Cu2+ enables p-doping, affording hole mobilities as high as 0.22 cm(2)V(-1) s(-1), which represents the highest reported values for water-soluble polythiophene materials. The interdisciplinary convergence between DNA nanotechnology and aqueous processed organic devices can provide important guidelines for the design of sustainable and efficient organic optoelectronic devices.