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Supercell Approach in Tight-Binding Calculation of Si and Ge Nanowire Bandstructures |
| GUAN Xi-Meng;YU Zhi-Ping |
| Institute of Microelectronics, Tsinghua University, Beijing 100084 |
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| Cite this article: |
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GUAN Xi-Meng, YU Zhi-Ping 2005 Chin. Phys. Lett. 22 2651-2654 |
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Abstract Energy bandstructures of [100] oriented Si and Ge quantum nanowires with various cross-sections are calculated by using the sp3d5s* tight-binding model with a supercell approach. Results are compared with those obtained by the first principles method (i.e., density functional theory, or DFT). The differences in the bandstructure between silicon and germanium nanowires are analysed and it is shown that germanium keeps indirect-bandgap and the silicon nanowire along the [100] direction becomes direct-bandgap when the wire diameter shrinks. It is shown in comparison with the available experimental data that the tight-binding method is adequate in predicting the bandstructure parameters relevant to the carrier transport in mesoscopic nanowire devices and is far superior to the DFT method in terms of computational cost.
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| Keywords:
73.21.Hb
71.15.Ap
78.67.Lt
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Published: 01 October 2005
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| PACS: |
73.21.Hb
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(Quantum wires)
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71.15.Ap
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(Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.))
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78.67.Lt
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(Quantum wires)
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