Charge Transfer, Luminescence, and Phonon Bottleneck in TiO2 Nanowires Computed by Eigenvectors of Liouville Superoperator

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• 作者：Shuping Huang ; Dmitri S. Kilin
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2014
• 出版时间：September 9, 2014
• 年：2014
• 卷：10
• 期：9
• 页码：3996-4005
• 全文大小：493K
• ISSN：1549-9626

文摘

A nonadiabatic excited state dynamics study of 鉄?01鉄?anatase TiO<sub>2sub> nanowire is obtained by combining density matrix in Liouville鈥揜edfield formalism and ab initio electronic structure calculations. The properties of eigenvectors of Liouville鈥揜edfield superoperator are investigated. The time evolutions of Kohn鈥揝ham orbital populations are obtained for different electronic excitations. The numerical solutions of the population changes over time are in agreement with the analytical results. The analytical and numerical results on the electron and hole relaxation rates are compared. The electron nonradiative relaxation to the bottom of conduction band involves Ti 3d orbitals, whereas the hole nonradiative relaxation to the top of valence band is mainly localized in surface O 2p orbitals. The rate of relaxation in nanowire is slower than in bulk TiO<sub>2sub> demonstrating phonon-bottleneck effect. Calculated emission spectrum has vanishing contribution from lowest energy excitation, which indicates charge transfer.