Abstract

The samples of the self-organized quantum dots, made of polar semiconductors, grown by the Stranski–Krastanow growth method, have the so called wetting-layer (WL). The lowest-energy extended states of the electronic excitations are expected to be the WL states. The coupling between these extended states and the electronic states localized in the individual quantum dots, may have an influence on the optical spectra of such samples in the sub-WL region of energy. This effect is studied, turning the attention first of all to the Frohlich's coupling between the electrons and polar optical phonons. The contribution of this interaction to the appearance of the sub-WL continuum in the optical spectra and to the level broadening of the localized states, pointed out in some experiments, is estimated.

Author Keywords: Quantum dots; Wetting-layer; Nanostructures; Optical spectra; Line-broadening; Continuous background; Self-assembled quantum dots

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*1 This is an expanded version of a paper accepted for publication in Microelectronics Journal, in press.