Theoretical study of the effects of strain balancing on the bandgap of dilute nitride InGaSbN/InAs superlattices on GaSb substrates
| Autor: | H. Hier, Keith W. Goossen, Ayub Fathimulla, Leye Aina, Nupur Bhargava, Victor A. Rodriguez-Toro, James Kolodzey, Ramsey Hazbun, L. Ramdas Ram-Mohan |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
Condensed matter physics Condensed Matter::Other Band gap Superlattice Nitride Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Atomic and Molecular Physics and Optics Cutoff frequency Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Lattice constant Lattice (order) Elastic modulus Quantum well |
| Zdroj: | Infrared Physics & Technology. 69:211-217 |
| ISSN: | 1350-4495 |
| DOI: | 10.1016/j.infrared.2015.01.023 |
| Popis: | The addition of nitrogen to III–V alloys has been widely studied as a method of modifying the band gap for mid-infrared (IR) applications. Lattice matching these alloys to convenient substrates such as GaSb, however, is challenging due to the significantly different lattice constants. One approach is to use InGaSbN/InAs grown on GaSb where the InGaSbN layer has a larger lattice constant than the substrate, and the InAs layer has a lower lattice constant, and thus the compressive and tensile stress of the superlattice layers can be balanced in a so called strained-layer superlattice. In this paper, we report InxGa1−xSb1−yNy/InAs strained-layer superlattices with type-II (staggered) energy offsets on GaSb substrates, where the design of the layer thickness is based on the lattice constants and the elastic moduli. Three different strain balance conditions are reported: fixed superlattice period thickness, fixed InAs well thickness, and fixed InxGa1−xSb1−yNy barrier thickness. Eight-band k · p simulations of these structures were used to analyze the superlattice miniband energies. For fully strain balanced InxGa1−xSb1−yNy/InAs superlattices lattice matched to the GaSb substrate, careful consideration of strain balance conditions was needed to achieve a lower effective miniband gap needed for longer cutoff wavelength detectors. For non-strained balanced InxGa1−xSb1−yNy/InAs superlattices, long-wavelength cutoff up to 8 μm can be achieved as part of a trade-off between the deleterious effects of strain and the reduction of the barrier band gap through N incorporation. |
| Databáze: | OpenAIRE |
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