Photoluminescence evolution in InAs/InP quantum dots grown by MOVPE

Self-assembled quantum dots of InAs have been grown on InP substrates by metal-organic vapour phase epitaxy. The effect of the growth temperature and the growth rate on the morphology and the optical properties of the quantum dots is studied using atomic force microscopy and photoluminescence spectroscopy. The spectral shape of the low temperature photoluminescence depends strongly on the growth conditions. A single peak, observed at a high growth rates, develops into two or even three distinct peaks for different samples grown at progressively lower growth rates. These findings weakly correlate with the observed size distribution of the quantum dots although the role of arsenic/phosphorous exchange at the Group-V sites may also be important. The temperature dependence of the photoluminescence spectra for the samples with a single peak is also discussed.