<title>Heterostructure optical phonons in dynamics of quantum dot electronic excitations: new experimental evidences</title>

Unusual coupling of heterostructure optical phonons and electronic excitations in quantum dots (QD's) was observed by photoluminescence spectroscopy in strain-induced InGaAs/GaAs QD's (SIQD's) and self-assembled InAs/GaAs QD's (SAQD's). Phonon-assisted interband transitions in SIQD's were found to be governed by zone center bulk GaAs TO and LO phonons via deformation potential interaction, whereas polar interaction was inessential. For SAQD's, a n-doped GaAs substrate was found to effect on QD intraband relaxation of carriers via coupling between them and substrate LO-phonon-plasmon modes at spacing between QD's and substrate as long as 100 nm.