We present an electronic structure and non-adiabatic excited state dynamics study of <001> anatase TiO2 nanowire (NW) by combining density matrix formalism and ab initio electronic structure calculations. Our results show that quantum confinement increases the energy gap as the dimension of TiO2 is reduced from the bulk to a NW with a diameter of several nanometres and that the probability of electronic transitions induced by lattice vibrations for the NW follows band gap law. The electron non-radiative relaxation to the bottom of the conduction band is involving Ti 3d orbitals, while the hole non-radiative relaxation of holes to the top of the valence band occurs by subsequent occupation of O 2p orbitals.
Bibliographical noteFunding Information:
This research was supported by South Dakota Governor’s Office of Economic Development, NSF award [EPS0903804] and DOE, BES – Chemical Sciences, NERSC Contract [DE-AC02-05CH11231], allocation award , , ‘Computational Modeling of Photo-catalysis and Photoinduced Charge Transfer Dynamics on Surfaces’.
- Electronic structure
- Non-adiabatic dissipative dynamics
- Quantum confinement
- TiO nanowires