Enhancing intergranular conductivity in polycrystalline semiconductor assembly via polythiophene use

We report here the synthesis and grafting of easily accessible catechol-terminated poly(3-hexylthiophenes) onto Al-doped ZnO particles (ZnO:Al) to obtain a performance-improved polycrystalline assembly. These macromolecular binding species favor electronic conduction from one grain to another. Resistivity measurements of the grafted ZnO:Al powders performed under compression show an increased conductivity as compared to the pure ZnO:Al powders. The catechol function terminating the polymer appears to play an important role on its effect by forming a strong covalent bond with the surface of the zinc oxide. In particular, the conductivity obtained under characteristic pressures of lamination processes gives 1–10 Ω cm, evidencing the great potential of such an approach for preparation of flexible or thermoreactive films. [Display omitted] •Improvement of the intergranular conductivity in a ZnO–Al powder by a low temperature process without sintering.•Synthesis of a “custom-made” catechol-terminated P3HT polymer.•Polymers grafted onto ZnO:Al nanoparticles via the catechol function.•Covalent grafting of a specific organic molecule to ZnO surface favors the alignment of its energy levels with that of ZnO.•Electronic conductivity increased by a decade compared to untreated ZnO:Al powder.