Epitaxial growth and optical characterization of InAs/InGaAsP/InP self-assembled quantum dots

Five stacks of InAs quantum dots (QDs) with InGaAsP barriers were grown on (100) InP and luminescence characteristics were analyzed. Cross-sectional transmission electron microscopy shows that small dots with a lateral size of similar to 30 nm and a height of similar to3 nm are formed with an areal density of similar to5 x 10(10) cm(-2). The QDs emit strong photoluminescence (PL) peaks in the range of 1.4-1.6 mum that can be controlled by nominal InAs thickness. The integrated PL intensity from QDs stays very high at room temperature as much as 20% of that at 10 K. At weak excitation, the carrier lifetimes are measured to be almost the same across the whole PL band at low temperature with a value of similar to4 ns and they remain at that value at room temperature. These characteristics strongly evidence that individual QDs are well isolated and have a strong carrier confinement at room temperature. (C) 2001 American Institute of Physics.