| Autor: |
M. Kamal-Saadi, Stanko Tomić, Eoin P. O'Reilly, A. Lindsay |
| Rok vydání: |
2002 |
| Předmět: |
|
| Zdroj: |
Semiconductor Science and Technology. 17:870-879 |
| ISSN: |
0268-1242 |
| Popis: |
We review how the tight-binding method provides a particularly useful approach to understand the electronic structure of GaInNAs alloys, and use it to derive a modified k?p model for the electronic structure of GaInNAs heterostructures. Using the tight-binding model, we first confirm that N forms a resonant defect level above the conduction band edge in Ga(In)As. We show that the interaction of the resonant N level with the conduction band edge accounts for the strong bandgap bowing observed in GaInNxAs1?x, in agreement with experimental analysis but contrary to some theoretical interpretations. We then use a Green function model to derive explicitly the two-level band-anti-crossing model describing the interaction between the resonant states and the conduction band edge in ordered Ga(In)NxAs1?x. We extend the Green function model to show that the conventional k?p model must be modified to include two extra spin-degenerate nitrogen states, giving a 10-band k?p model to describe the band structure of GaNAs/GaAs and related heterostructures. We describe how this 10-band model provides excellent quantitative agreement with a wide range of experimental data and finally discuss briefly the effects of disorder on the electronic structure in dilute nitride alloys. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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