Approximate ab initio calculations of electronic structure of amorphous silicon


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Durandurdu M. , DRABOLD D., MOUSSEAU N.

PHYSICAL REVIEW B, cilt.62, ss.15307-15310, 2000 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 62 Konu: 23
  • Basım Tarihi: 2000
  • Doi Numarası: 10.1103/physrevb.62.15307
  • Dergi Adı: PHYSICAL REVIEW B
  • Sayfa Sayısı: ss.15307-15310

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.