Contactless electroreflectance and photoluminescence study of highly strained InGaAs(Sb) double quantum wells

InGaAs(Sb)/GaAs double quantum wells (DQWs) structures grown with Sb assistance under different Sb/V ratios by metalorganic vapor-phase epitaxy (MOVPE) have been characterized as a function of temperature in the temperature range between 17 and 300 K by the techniques of contactless electroreflectance (CER) and photoluminescence (PL). The interband transition energies are determined via a lineshape fit to the CER spectra and exhibit a slight redshift with the incorporation of Sb. The PL spectra show redshifted peak location with decreasing intensity and broadened full width at half maximum with increasing Sb/V ratio during MOVPE growth. A careful analysis of CER and PL spectra has led to the identification of various excitonic transitions. The anomalous temperature variation of PL spectra has been attributed to the carrier localization effect resulted from the presence of Sb clusters at the QW interfaces. The parameters that describe the temperature dependence of the interband transition energies are evaluated and discussed.