Discovering new M-quinolate materials: theoretical insight into understanding the charge transport, electronic, self-aggregation properties in M-quinolate materials (M = Li, Na, K, Rb, Cs, Cu, Ag, and Au)

A series of M-quinolate complexes were theoretically investigated to understand the effect of metal ions on electronic and charge transport properties by employing density functional theory simulation. It was found that both electronic and carrier transport properties in M-quinolate materials significantly depend on singly oxidized metal ions. In particular, Csq apparently showed an excellent advantage over other M-quinolate materials (M = Li, Na, K, Rb, Cs, Cu, Ag, and Au) in terms of electron mobility and injection. In addition, the dimerization and vertical detachment energies of all M-quinolate materials were compared to understand self-aggregation effect on carrier transport. As a result, it is expected that Csq is not only likely to be present in dimer form, but also reduce the density of electron traps in electron transporting materials.