Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1784409 | Infrared Physics & Technology | 2013 | 5 Pages |
•Extension of the two-component superlattice empirical pseudopotential method (SEPM).•Model includes interface layers and As-content of the barrier and the interface.•Accurate bandgap prediction for InAs/GaSb superlattices with thin layers.
For the design of InAs/GaSb superlattice (SL) heterojunction infrared photodetectors with very low dark current we have extended the standard two-component superlattice empirical pseudopotential method (SEPM) and implemented a four-component model including interface layers. For both models, the calculated bandgap values for a set of SL samples are compared to bandgaps determined by photoluminescence measurements. While the bandgap resulting from the two-component model agrees well with experimental data for SL structures with individual layer thicknesses of 7 monolayers and more, we show that for SLs with thinner GaSb layers the four-component SEPM model is accurate, when the As-content in the interface and barrier layers is included in the model.