Effects of growth interruption on the evolution of InAs/InP self-assembled quantum dots

We investigated the change in the structural and optical properties of InAs/InP quantum structures during growth interruption (GI) for various times and under various atmospheres in metalorganic chemical vapor deposition. Under AsH3 + H2 atmosphere, the mass transport for the 2D-to-3D transition was observed during the GI. Photoluminescence peaks from both quantum dots (QDs) and quantum wells were observed from the premature QD samples. The fully developed QDs showed the two distinct temperature regimes in the PL peak position, full width at half maximum (FWHM) and wavelength-integrated peak intensity. The two characteristic activation energies were obtained from the InAs/InP QDs: ∼10 meV for intra-dot excitation and 90 ∼ 110 meV for the excitation out of the dots, respectively. It was also observed that the QD evolution kinetics could be suppressed in PH3 + H2 and H2 atmospheres. The proper control of GI time and atmosphere might be a useful tool to further improve the properties of QDs.