Elastic light scattering by semiconductor quantum dots of arbitrary shape

Abstract

Elastic light scattering by low-dimensional semiconductor objects is investigated theoretically. The differential cross section of resonant light scattering on excitons in quantum dots is calculated. The polarization and angular distribution of scattered light do not depend on the quantum-dot form, sizes and potential configuration if light wave lengths exceed considerably the quantum-dot size. In this case the magnitude of the total light scattering cross section does not depend on quantum-dot sizes. The resonant total light scattering cross section is about a square of light wave length if the exciton radiative broadening exceeds the nonradiative broadening. Radiative broadenings are calculated.

Resonant Light Absorption by Semiconductor Quantum Dots

“…The results for the cross-sections of light scattering on QD, obtained with the help of the quasiclassic method, coincide with the lowest approximation on the light-electron interaction with the results of the quantum perturbation theory [10]. However, the quasiclassic method allows to obtain also the cross-section of light absorption by a QD.…”

“…The Case of the Exciton Γ 6 × Γ 7 in a QD Let us consider an exciton consisting of an electron from twofold degenerated conductive band Γ 6 and a hole from twofold degenerated valence band Γ 7 chipped of by the spinorbital interaction in T d class crystals. The exciton Γ 6 × Γ 7 (see [10,11]) is the most simple object in contrast to excitons containing light and heavy holes. All the measurable values do not depend on the direction of vectors relatively of crystallographic axes, that is, a crystal plays a role of an isotropic medium.…”

“…The light elastic scattering on a QD of arbitrary form and sizes in a resonance with excitons is investigated in [10], where the quantum perturbation theory is used. However, the quantum method does not allow to get out of the lowest order on the light-electron interaction and to calculate corrections to the exciton energy due to that interaction.…”

Scattering Imaging of Single Quantum Dots with Dark-Field Microscopy

“…Imaging of single quantum dots (QDs) has been readily achieved by standard fluorescence microscopy and many photophysical details of QDs and bioimaging applications have been uncovered and realized with such methods. − Scattering imaging is a promising alternative to probe nanomatters such as gold/silver nanoparticles or nanorods with sizes of tens of nanometers based on their localized surface plasmon resonance. − However, scattering imaging of QDs with diameters less than 10 nm has not yet been achieved although elastic light scattering by QDs has been theoretically investigated. , Most recently, Kukura et al recorded the extinction images of individual QDs by a laser-based scanning point detector . Those authors and other researchers imply that the scattering cross section of QDs is much smaller than the absorption cross section and suggest that light scattering is not suitable for imaging individual QDs.…”