The great potential of coupled substitutions in In2O3 for the generation of bixbyite-type transparent conducting oxides, In2−2xMxSnxO3

The study of coupled substitution of In3+ by Sn4+/M2+ species in In2O3 has allowed In2−2xSnxMxO3 solid solutions with bixbyite structure to be synthesized for M=Ni, Mg, Zn, Cu and Ca. The latter exhibit a rather broad homogeneity range and are characterized by an ordered cationic distribution. More importantly, these novel oxides are transparent conductors, and among them the Zn and Cu phases show a great potential, since one observes a semi-metallic behavior with conductivity up to 3×102 and 3×103 (Ω cm)−1, respectively, to be compared to 2×103 (Ω cm)−1 for reduced ITO. Moreover, in contrast to the latter no reducing conditions are required for reaching such performances.