Electromodulation spectroscopy of interband transitions in GaInNAsSb/GaAs quantum wells with high indium content

Abstract Contactless electroreflectance (CER) has been applied to study the optical transitions in as‐grown and annealed GaInNAsSb/GaAs QWs with 2.25% of nitrogen, high indium content (34%) and antimony flux varied from zero to 1.0 × 10^–7 beam equivalent pressure torr (it corresponds to antimony content varied from 0 to 2%). It has been observed that broadening of the CER resonance related to the ground state transition decreases about three times (from ∼60 meV to 20 meV) after the incorporation of antimony into GaInNAs/GaAs QWs. Moreover, it has been found that the broadening parameter does not decrease with the rise of antimony content from 0.5% to 2.0%. It means that only 0.5% Sb is enough to improve the optical quality of GaInNAs/GaAs QWs. In addition, it has been observed that post growth annealing significantly improves the optical quality of these QWs and shifts to blue all QW transitions. By matching the QW transition energies with those obtained from theoretical calculations performed within the effective mass approximation the conduction band offset in these QWs has been found to be close to 80%. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)