Related papers: Exciton fine structure in CdSe nanoplatelets using…
We study the band-edge exciton fine structure and in particular its bright-dark splitting in colloidal semiconductor nanocrystals by four different optical methods based on fluorescence line narrowing and time-resolved measurements at…
The optical spectra of CdSe nanocrystals up to 55 A in diameter are analyzed in a wide range of energies from the fine structure of the low-energy excitations to the so-called high-energy transitions. We apply a symmetry-based method in two…
Theory of electronic and optical properties of exciton and bi-exciton complexes confined in CdSe spherical nanocrystals is presented. The electron and hole states are computed using atomistic $sp^3d^5s^*$ tight binding Hamiltonian including…
The structure of the ground state exciton of Cd(Se,Te) quantum dots embedded in ZnTe matrix is studied experimentally using photoluminescence spectroscopy and theoretically using ${\bf k}\cdot{\bf p}$ and configuration interaction methods.…
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. We validate our theory model by comparing results of computed exciton…
CdSe nanoplatelets show perfectly quantized thicknesses of few monolayers. They present a situation of extreme, yet well defined quantum confinement. Due to large dielectric contrast between the semiconductor and its ligand environment,…
We report on polarization-resolved resonant photoluminescence (PL) spectroscopy of bright (spin-1) and dark (spin-2) excitons in colloidal CdSe nanocrystal quantum dots. Using high magnetic fields to 33 T, we resonantly excite (and…
Exciton fine structure splitting in semiconductors reflects the underlying symmetry of the crystal and quantum confinement. Since the latter factor strongly enhances the exchange interaction, most work has focused on nanostructures. Here,…
We develop a general method to calculate Zeeman splittings of electrons and holes in semiconductor nanostructures within the tight-binding framework. The calculation is carried out in the electron-hole picture and is extensible to the…
Exciton luminescence of a CdSe quantum dot (QD) inserted in a ZnSe nanowire is strongly influenced by the dark exciton states. Because of the small size of these QDs (2-5nm), exchange interaction between hole and electron is highly enhanced…
A comprehensive study of excitonic properties of 2D layered perovskites is provided, with an emphasis on understanding and controlling the exciton fine structure. First, an overview of the optical properties is presented, discussing the…
Colloidal semiconductor nanoplatelets exhibit quantum size effects due to their thickness of only few monolayers, together with strong optical band-edge transitions facilitated by large lateral extensions. In this article we demonstrate…
We present a comparative study of two self-assembled quantum dot (QD) systems based on II-VI compounds: CdTe/ZnTe and CdSe/ZnSe. Using magneto-optical techniques we investigated a large population of individual QDs. The systematic…
Although both epitaxial quantum dots (QDs) and colloidal nanocrystals (NCs) are quantum-confined semiconductor nanostructures, so far they have demonstrated dramatically-different exciton fine structure splittings (FSSs) at the cryogenic…
Recently, the fabrication of CdSe nanoplatelets became an important research topic. Nanoplatelets are often described as having a similar electronic structure as 2D dimensional quantum wells and are promoted as colloidal quantum wells with…
Luminescent colloidal CdSe nanorings are a new type of semiconductor structure that have attracted interest due to the potential for unique physics arising from their non-trivial toroidal shape. However, the exciton properties and dynamics…
The electronic and optical properties of spherical nanoheterostructures are studied within the semi-empirical $sp^{3}s^{*}$ tight-binding model including the spin-orbit interaction. We use a symmetry-based approach previously applied to…
We investigated the nonlinear optical properties of CdSe/CdS nanoplatelets in the vicinity of heavy hole and light hole exciton resonances. The two color pump-probe technique was applied. The first intense pulse created non-equilibrium…
We investigate the lowest many-body excited states in carbon nanotubes by means of ab initio calculations. On the basis of these calculations and an additional theoretical analysis of the excitons, we demonstrate that the splitting between…
Atomistically detailed computational studies of nanocrystals, such as those derived from the promising lead-halide perovskites, are challenging due to the large number of atoms and lack of symmetries to exploit. Here, focusing on…