(211)-Orientation Preference of Transparent Conducting In₂O₃:Sn Films and Its Formation Mechanism

Dominantly (211)-oriented In(2)O(3):Sn (ITO) transparent conducting oxide (TCO) films were first fabricated at high sputtering power in the weak reducing ambient with superior electrical and optical properties. The dependence of ITO film orientation on growth condition was systematically investigated, and the formation mechanism was studied by surface energy calculation and band structure simulation. The unique properties of the (211)-oriented films should be ascribed to the richest In-terminated surface of the (211) plane, which is tightly correlated with the comparably highest surface energy and highest conduction band surface comparing with the other two typical planes of (222) and (400). The as-prepared (211)-oriented ITO films with the In-rich ending atoms on the surface are of great significance for the transparent electrode applications.