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Optical spectra of nitride quantum‐dot systems: From tight‐binding states to many‐body effects
Author(s) -
Seebeck J.,
Lorke M.,
Schulz S.,
Schuh K.,
Gartner P.,
Jahnke F.
Publication year - 2011
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.201147160
Subject(s) - dephasing , delocalized electron , quantum dot , condensed matter physics , tight binding , coulomb , physics , density of states , spectral line , wetting layer , dipole , phonon , molecular physics , atomic physics , quantum mechanics , electronic structure , electron
A microscopic theory for optical properties of self‐assembled quantum‐dot systems is presented. For nitride‐based material systems, the single‐particle states are determined from atomistic tight‐binding (TB) calculations. This includes not only localized quantum‐dot states but also delocalized wetting‐layer states, since both contribute to the optical properties and are coupled via interaction processes. The TB wave functions are used to calculate matrix elements for optical dipole transitions as well as Coulomb and LO–phonon interaction of carriers. Absorption and gain spectra are investigated via a solution of the semiconductor Bloch equations including Coulomb interaction effects as well as dephasing due to carrier interaction with LO–phonons. Numerical results are presented for InN/GaN QD‐WL systems and allow to investigate the excitation‐density dependence of the optical spectra for this particular system.