First-Principles Study of Titania Nanoribbons: Formation, Energetics, and Electronic Properties

The geometric, electronic, and magnetic properties of titania nanoribbons (TiO(2)NRs) are investigated with use of first-principles calculations within density-functional theory. The TiO(2)NRs formed by cutting ultrathin TiO2 nanosheet along armchair and zigzag axes have high energetic stability. Zigzag TiO(2)NRs are more preferable than armchair ones. The electronic structures of TiO(2)NRs highly depend on the growth orientation and the ribbon width. Introducing oxygen vacancy defects into the edges of zigzag TiO(2)NRs under poor oxygen conditions can reduce the band gap and trigger the spin-polarization of edge states. These TiO(2)NRs with well-defined atomic structures, high stability, and tunable electronic properties are expected to have potential applications in solar cells, spintronic devices, and sensors.