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Semiconductor nanocrystals and embedded quantum dots: Electronic and optical properties
Author(s) -
Schulz S.,
Schumacher S.,
Czycholl G.
Publication year - 2007
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200674608
Subject(s) - wurtzite crystal structure , quantum dot , hamiltonian (control theory) , condensed matter physics , semiconductor , dipole , oscillator strength , electronic structure , physics , excitation , materials science , quantum mechanics , mathematics , mathematical optimization , diffraction , spectral line
A tight‐binding model for semiconductor quantum dots (QD) consisting of a small gap semiconductor material A embedded within a larger gap material B is used to determine the bound, localized one‐particle QD‐states. The form and symmetry properties of these states and their dependence on form, size and composition of the QDs are discussed. The Coulomb and dipole matrix elements between these states are calculated so that a many‐body Hamiltonian is derived describing the elctronic properties of the QDs and the coupling to an applied (optical) electric field. Truncating the many‐particle Hilbert space by taking into account only a finite number of localized electron and hole states the many‐body Hamiltonian can be solved exactly. The resulting excitation spectrum and optical properties are presented and discussed. The method is, in particular, applied to CdSe QDs embedded in ZnSe with zincblende structure, to CdSe nanocrystals, and to InN QDs embedded in GaN with wurtzite structure. For the latter case also the influence of an intrinsic piezoelectric field and of the special symmetry properties of the wurtzite structure are discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)