Charge transport ink composition

Abstract

This invention provides a charge-transfer ink composition that can provide a charge-transfer thin film with excellent charge transport properties. The ink composition comprises: metal oxide nanoparticles: oxides of metals selected from the group consisting of Zn, Mg, Ti, Zr, Sn, Ga, Fe, Ta, Nb, Y, Mo, W, Pb, In, Bi and Sr; and at least one metal oxide nanoparticle from the group consisting of a complex of at least two of the aforementioned metals, and a salt consisting of a cation represented by the following formula (A2-3) and an anion represented by the following formula (B1-1), the salt having a topological polar surface area (TPSA) of 1 or more, and an organic solvent.