Nucleation and growth evolution of InP dots on InGaP/GaAs

We have investigated the evolution in the heteroepitaxy of InP on InGaP/GaAs (0 0 1) layers from the initial formation of a strained wetting layer (WL) up to the development of quantum dots. Atomic force microscopy and RHEED as well as continuous and time-resolved photoluminescence measurements provide evidence of four main stages for InP growth evolution. Our results indicate that the InP dot formation occurs according to the Stranski-Krastanov growth mode coupled to a WL erosion mechanism driven by the spatially variable strain field present in the WL. Moreover, the correlation of morphological and optical data indicates the stability of dot shapes and interfaces in this system.