The effect of organic additives on the intergranular conductivity of Al-doped ZnO

Abstract

The development of ink-based solutions as alternative routes to vacuum-based deposition techniques requires methods to improve their intergranular conductivity without thermal sintering. The effect of organic additives on the interparticle electron transfer between grains of an Al-doped ZnO powder was studied. The resistivity of the modified powders was measured as a function of compression to reach a reproducible state. The surface adsorption of selected molecules strongly enhances intergranular electron transfer, up to a factor of 20. This improvement has been linked to the decrease of the intergranular potential barrier height, associated with the energy distance between the Fermi level of the oxide and the LUMO of the molecules.