2010/01/06 by P. Horodyská, P. Horodyska, Petr Němec +6 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Biexciton #Chalcogenide Semiconductor Thin Films #Chemical physics #Condensed matter physics #Dynamics (music) #Exciton #Materials science #Physics #Quantum Dots Synthesis And Properties #Quantum dot #Quantum mechanics #Semiconductor Quantum Structures and Devices #Spin (aerodynamics) #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.81.045301
published as Phys. Rev. B 81, 045301 (2010). · 24 pages, 10 figures
openalex publication_date 2010/01/06 · arxiv created 2010/01/08 · arxiv updated 2015/05/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Exciton spin dynamics in quasispherical CdS quantum dots is studied in detail experimentally and theoretically. Exciton states are calculated using the six-band k\ensuremath⋅p Hamiltonian. It is shown that for various sets of Luttinger parameters, when the wurtzite lattice crystal-field splitting and Coulomb interaction between the electron-hole pair are taken into account exactly, both the electron and hole wave functions in the lowest exciton state are of S type. This rules out the spatial-symmetry-induced origin of the dark exciton in CdS quantum dots. The exciton bleaching dynamics is studied using time- and polarization-resolved transient absorption technique of ultrafast laser spectroscopy. Several samples with a different mean size of CdS quantum dots in different glass matrices were investigated. This enabled the separation of effects that are typical for one particular sample from those that are general for this type of material. The experimentally determined dependence of the electron-spin-relaxation rate on the radius of quantum dots agrees well with that computed theoretically.