Interface phenomena at semiconductor heterojunctions: Local-density valence-band offset in GaAs/AlAs
1987; American Physical Society; Volume: 35; Issue: 18 Linguagem: Inglês
10.1103/physrevb.35.9871
ISSN1095-3795
AutoresS. Massidda, B. I. Min, A. J. Freeman,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoThe valence-band offset \ensuremath{\Delta}${E}_{v}$ at the lattice-matched GaAs/AlAs(001) interface is derived from highly precise self-consistent all-electron local-density band-structure calculations of the (GaAs${)}_{n}$(AlAs${)}_{n}$(001) superlattices (with n\ensuremath{\le}3). We calculate \ensuremath{\Delta}${E}_{v}$ by using the core levels---available uniquely from an all-electron approach---as reference energies. Since these are experimentally accessible quantities, a direct comparison with experiment is, in principle, possible. We find that \ensuremath{\Delta}${E}_{v}$=0.5\ifmmode\pm\else\textpm\fi{}0.05 eV, in very good agreement with recent experimental results (\ensuremath{\Delta}${E}_{v}$=0.45--0.55 eV). Calculated core-level shifts are also compared with experiment. These results, which are closely related to changes in the charge-density distribution at the interface, contribute to understanding the underlying mechanism of the band discontinuity.
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