Measurements of the transition energies of GaAsSb quantum well samples with different barrier configurations reveal that the conduction band offset of the coherently strained GaAs1-ySby/GaAs heterojunction grown on GaAs has a zero crossing at a Sb mole fraction of y=0.43±0.07. A type-I band alignment is formed for lower Sb mole fractions and a type-II band alignment is formed for higher Sb mole fractions. This occurs as a consequence of a considerable amount (58%) of the -1.58eV bandgap bowing being distributed to the conduction band. As a suitable active material for 1.3 μm emission, pseudomorphic GaAs0.643Sb0.357 grown on GaAs is determined to have a weak, 23±23 meV, type-I conduction band offset and a bandgap energy of 928±4 meV.
|Original language||English (US)|
|Number of pages||8|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Nov 2004|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics