Electronic structure of intentionally disordered AlAs/GaAs superlattices
- National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
We use realistic pseudopotentials and a plane-wave basis to study the electronic structure of nonperiodic, three-dimensional, 2000-atom (AlAs){sub {ital n}}/(GaAs){sub {ital m}} (001) superlattices, where the individual layer thicknesses {ital n},{ital m}{element_of}{l_brace}1,2,3{r_brace} are randomly selected. We find that while the band gap of the equivalent ({ital n}={ital m}=2) {ital ordered} superlattice is indirect, random fluctuations in layer thicknesses lead to a {ital direct} gap in the planar Brillouin zone, strong wave function localization along the growth direction, short radiative lifetimes, and a significant band-gap reduction, in agreement with experiments on such intentionally grown disordered superlattices.
- DOE Contract Number:
- AC36-83CH10093
- OSTI ID:
- 27868
- Journal Information:
- Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 13 Vol. 74; ISSN 0031-9007; ISSN PRLTAO
- Country of Publication:
- United States
- Language:
- English
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