GaAsSb/GaAs type-II quantum well and its application on ∼1.3 μm laser

Abstract

The band offset of the type-ll GaAso.,Sbo.,1GaAs quantum well (Qw) is studied. We propose an extrapolation method to remove the band-bending effect and determine the flat-band transition energy of the type-I1 QW from photoluminescence (PL) measurement. Then, we compare the PL peak energies of the type-II GaAso.+bo,,/GaAs QW and the type4 Alo.,G%,7As/ GaAso.,Sbo,l QW to obtain the strained band gap energy of GaAso.7Sbo.3 and the valence-band-offset ratio of the type-ll QW. The obtained band gap energy and valence-band-offset ratio are 1.01 eV and 1.15. GaAsSbiGaAs double-quantum-well lasers were also grown and fabricated. The laser demonstrates a very low threshold current density of 210 Ncm' with an emission wavelength of 1.28pm.