Open AccessInterplay between multipole expansion of exchange interaction and Coulomb correlation of exciton in colloidal II–VI quantum dots
Author(s) -
Petr Klenovský,
Jakub Valdhans,
Lucie Krejčí,
Miroslav Valtr,
Petr Klapetek,
О. М. Федотова
Publication year - 2022
Publication title -
electronic structure
Language(s) - English
Resource type - Journals
ISSN - 2516-1075
DOI - 10.1088/2516-1075/ac5b7e
Subject(s) - wurtzite crystal structure , quantum dot , exciton , multipole expansion , coulomb , biexciton , condensed matter physics , photoluminescence , exchange interaction , molecular physics , dipole , materials science , physics , atomic physics , nanotechnology , quantum mechanics , optoelectronics , electron , ferromagnetism , diffraction
We study the effect of Coulomb correlation on the emission properties of the ground state exciton in zincblende CdSe/ZnS core–shell and in wurtzite ZnO quantum dots (QDs). We validate our theory model by comparing results of computed exciton energies of CdSe/ZnS QDs to photoluminescence and scanning near-field optical microscopy measurements. We use that to estimate the diameter of the QDs using a simple model based on infinitely deep quantum well and compare the results with the statistics of the atomic force microscopy scans of CdSe/ZnS dots, obtaining excellent agreement. Thereafter, we compute the energy fine structure of exciton, finding striking difference between properties of zincblende CdSe/ZnS and wurtzite ZnO dots. While in the former the fine structure is dominated by the dipole terms of the multipole expansion of the exchange interaction, in the latter system that is mostly influenced by Coulomb correlation. Furthermore, the correlation sizeably influences also the exciton binding energy and emission radiative rate in ZnO dots.