Theoretical modelling of quaternary GaInAsSb/GaAs self-assembled quantum dots

InAs/GaAs quantum dots exposed to Sb after growth exhibit spectral changes. We study in the present paper an idealized nanostructure consisting of a homogeneous distribution of the quaternary GaInAsSb surrounded by a barrier of GaAs. We find that the valence band offset is a critical parameter in modelling its electronic structure. Depending on this value, we predict a transition from type-I to type-II band alignment at a different Sb concentration. The addition of Sb to reduce the transition energy while keeping a type-I alignment is only of benefit at low Sb concentration.MICINN projects TEC2008-06756-C03-01/02/TECMICINN CONSOLIDER INGENIO 2010 CSD2006-0019 and CSD2009-00013Junta de Andalucía PAI research groups TEP-120 and TIC-145 project P08-TEP-03516Comunidad Autónoma de Madrid S2009ESP-15