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We used first-principles methods to generate amorphous TiO₂ (a-TiO₂) models and our simulations lead to chemically ordered amorphous networks. We analyzed the structural, electronic, and optical properties of the resulting structures and compared with crystalline phases. We propose that two peaks found in the Ti–Ti pair correlation correspond to edge-sharing and corner-sharing Ti–Ti pairs. Resulting coordination numbers for Ti (∼6) and O (∼3) and the corresponding angle distributions suggest that local structural features of bulk crystalline TiO₂ are retained in a-TiO₂. The electronic density of states and the inverse participation ratio reveal that highly localized tail states at the valence band edge are due to the displacement of O atoms from the plane containing three neighboring Ti atoms; whereas, the tail states at the conduction band edge are localized on over-coordinated Ti atoms. The …