Ab-initio Calculation of Structural and Electrical Properties of Amorphous TiO2
نویسندگان
چکیده
We used first-principle simulation methods to generate amorphous TiO2 (a-TiO2) models and obtained chemically-ordered amorphous networks. We analyzed the structural and the electronic properties of the resulting computationally generated structures. We propose that two peaks found in the Ti-Ti pair correlation correspond to the edge-sharing and the corner-sharing Ti-Ti pairs. Resulting coordination numbers for Ti (6) and O (3) and the corresponding angle distributions suggest that local structural features in bulk crystalline TiO2 are retained in our aTiO2 models. 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 Γ-point electronic gap of approximately 2.0 eV is comparable to calculated results for bulk crystalline TiO2.
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