Self-assembled quantum dots: level broadening and continuous background in the sub-wetting layer region of electron energy

The samples of the self-organized polar semiconductor quantum dots, grown by the Stranski–Krastanow growth method, contain the wetting layer, representing the lowest barrier for electrons to get to the extended motion states. The scattering of electrons between the extended states and the electronic states localized in the individual quantum dots, with emission or absorption of optical phonons via Fröhlichʹs coupling, may influence the optical spectra of such samples in the sub-wetting layer region of the electronic energy. The contribution of this interaction to the appearance of the sub-wetting layer continuum in the optical spectra and to the level broadening of the localized states, is studied.