We report a combined theoretical and experimental investigation of quantum confinement effects on the E-1 interband structures in the optical spectra of Ge quantum dots. The experimental average radius goes from approximate to 12 to approximate to 60 Angstrom. A blueshift of the E-1 absorption peak (up to 0.1 eV) and a strong reduction in the oscillator strength, are measured effects of the quantum confinement. The theoretical analysis is performed for nanocrystals up to 15 Angstrom through a semi-empirical tight-binding approach. We overcome the single-particle scheme including, in a perturbative approach. the Coulomb electron-hole interaction which induces a red-shift of the E-1 peak with respect to the one-electron calculation.
Optical properties of germanium quantum dots / M. Palummo, G. Onida, R. Del Sole, A. Stella, P. Tognini, P. Cheyssac, R. Kofman. - In: PHYSICA STATUS SOLIDI B-BASIC RESEARCH. - ISSN 0370-1972. - 224:1(2001), pp. 247-251. [10.1002/1521-3951(200103)224:1<247::AID-PSSB247>3.0.CO;2-O]
Optical properties of germanium quantum dots
G. OnidaSecondo
;
2001
Abstract
We report a combined theoretical and experimental investigation of quantum confinement effects on the E-1 interband structures in the optical spectra of Ge quantum dots. The experimental average radius goes from approximate to 12 to approximate to 60 Angstrom. A blueshift of the E-1 absorption peak (up to 0.1 eV) and a strong reduction in the oscillator strength, are measured effects of the quantum confinement. The theoretical analysis is performed for nanocrystals up to 15 Angstrom through a semi-empirical tight-binding approach. We overcome the single-particle scheme including, in a perturbative approach. the Coulomb electron-hole interaction which induces a red-shift of the E-1 peak with respect to the one-electron calculation.Pubblicazioni consigliate
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