By using an ab initio calculation, it is found that the variation of the fundamental band gap of (α-GaN)n / (α-AlN))n (0001) superlattices is remarkably different from that of (β-GaN))n / (β- A1N))n (001) superlat...By using an ab initio calculation, it is found that the variation of the fundamental band gap of (α-GaN)n / (α-AlN))n (0001) superlattices is remarkably different from that of (β-GaN))n / (β- A1N))n (001) superlattices. The difference in band gap behaviors was shown to be due to the internal electric fields induced by the spontaneous polarizations in α-GaN and α-AlN. In addition, the valence-band offsets at the interfaces of these superlattices are also determined. The results are in good agreement with those available from experimental data.展开更多
文摘By using an ab initio calculation, it is found that the variation of the fundamental band gap of (α-GaN)n / (α-AlN))n (0001) superlattices is remarkably different from that of (β-GaN))n / (β- A1N))n (001) superlattices. The difference in band gap behaviors was shown to be due to the internal electric fields induced by the spontaneous polarizations in α-GaN and α-AlN. In addition, the valence-band offsets at the interfaces of these superlattices are also determined. The results are in good agreement with those available from experimental data.
