Approximate ab initio calculations of electronic structure of amorphous silicon
PHYSICAL REVIEW B, cilt.62, sa.23, ss.15307-15310, 2000 (SCI-Expanded)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 62 Sayı: 23
- Basım Tarihi: 2000
- Doi Numarası: 10.1103/physrevb.62.15307
- Dergi Adı: PHYSICAL REVIEW B
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.15307-15310
- Abdullah Gül Üniversitesi Adresli: Hayır
Özet
We report on oh initio calculations of electronic states of two large and realistic models of amorphous silicon generated using a modified version of the Wooten-Winer-Weaire algorithm and relaxed, in both cases, with a Keating and a modified Stillinger-Weber potentials. The models have no coordination defects and a very narrow bond-angle distribution. We compute the electronic density-of-states and pay particular attention to the nature of the band-tail states around the electronic gap. All models show a large and perfectly clean optical gap and realistic Urbach tails. Based on these results and the extended quasi-one-dimensional stringlike structures observed for certain eigenvalues in the band tails, we postulate that the generation of model a-Si without localized states might be achievable under certain circumstances.