GaInSb/InAs/AlSb quantum wells with InSb- and GaAs-like interfaces investigated by temperature- and magnetic field-dependent photoluminescence

Abstract

GaInSb/InAs/AlSb quantum wells (QWs) with typical InSb- and GaAs-like interfaces (IFs) are investigated by temperature- and magnetic field-dependent photoluminescence (PL), respectively. The results show that (i) as temperature rises the PL energy of the QWs with either InSb- or GaAs-like IFs blueshifts slightly below 50 K but redshifts above and broadens rapidly, and the mechanism behind this is correlated to the IF roughness-related layer thickness fluctuation equivalent to a localization energy of about 9.5 meV; (ii) the PL diminishes monotonously as magnetic field rises except for the delocalized PL process of the InSb-like IF QWs, and the magnetic field-induced PL quenching is attributed to the IF roughness-induced electron-hole separation in the type-II QWs; and (iii) the magnetic field-dependent PL energy follows a typical excitonic diamagnetic shift for both located and dislocated states, and the deduced exciton binding energy, reduced effective mass, and average wavefunction extent are insensitive to the IF type. Comparison of different IF-type GaInSb/InAs QWs indicates that while the PL of the InSb-like IF sample contains type-I component as the IF confines heavy holes and acts as pseudo-barrier for electrons, leading to the coexistence of electrons and holes at the IFs, the IF-type does not affect the carrier localization and the in-plane excitonic behavior obviously.