MOVPE growth of InAs quantum dots for mid-IR applications

InAs quantum dots (QDs) grown on InxGa1-xAs/InP matrix by low pressure metal organic vapor phase epitaxy (LP-MOVPE) in nitrogen ambient were studied. Formation of the InAs QDs with different growth conditions was investigated. To improve the dot size uniformity, a two-step growth method was used and investigated. It is found that morphology of the InAs QDs formed on such InxGa1-xAs/InP matrix is very sensitive to the growth conditions. InAs QDs with high density of 1.3 × 1010 cm−2 are grown by using S-K growth method with fast growth rate. Using the two-step growth method, the InAs QDs size uniformity improves by 63% and 110% compared that of the dots grown by ordinary S-K method and ALE method, respectively. Narrow photoluminescence (PL) emission spectrum of the QDs grown by using the two-step growth method, is received. FWHM of the PL curve is measured at 26 meV and the peak emission wavelength is larger than 2.3 μm at 77 K.