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Extended excitons and compact heliumlike biexcitons in type-II quantum dots KU Leuven
We have used magnetophotoluminescence measurements to establish that InP/GaAs quantum dots have a type-II (staggered) band alignment. The average excitonic Bohr radius and the binding energy are estimated to be 15 nm and 1.5 meV, respectively. When compared to bulk InP, the excitonic binding is weaker due to the repulsive (type-II) potential at the heterointerface. The measurements are extended to over almost 6 orders of magnitude of laser ...
Excitons, trions, and biexcitons in transition-metal dichalcogenides Universiteit Antwerpen
The influence of a perpendicular magnetic field on the binding energy and structural properties of excitons, trions, and biexcitons in monolayers of semiconducting transition metal dichalcogenides (TMDs) is investigated. The stochastic variational method (SVM) with a correlated Gaussian basis is used to calculate the different properties of these few-particle systems. In addition, we present a simplified variational approach which supports the ...
Reply to "Comment on `Excitons, trions, and biexcitons in transition-metal dichalcogenides: Magnetic-field dependence'" Universiteit Antwerpen
In the Comment, the authors state that the separation of the relative and center of mass variables in our work is not correct. Here we point out that there is a typographical error, i.e., qi instead of -e, in two of our equations which, when corrected, makes the Comment redundant. Within the ansatzes mentioned in our paper all our results are correct, in contrast to the claims of the Comment.
Signatures of subband excitons in few-layer black phosphorus Universiteit Antwerpen
Recent experimental measurements of light absorption in few-layer black phosphorus (BP) revealed a series of high and sharp peaks, interspersed by pairs of lower and broader features. Here, we propose a theoretical model for these excitonic states in few-layer BP within a continuum approach for the in-plane degrees of freedom and a tight-binding approximation that accounts for interlayer couplings. This yields excitonic transitions between ...
Fine structure of nearly isotropic bright excitons in InP/ZnSe colloidal quantum dots Universiteit Gent
Tuning energy splitting and recombination dynamics of dark and bright excitons in CdSe/CdS dot-in-rod colloidal nanostructures Universiteit Gent
Distinctive g-factor of Moire-confined excitons in van der Waals heterostructures Universiteit Antwerpen
We investigated the valley Zeeman splitting of excitonic peaks in the microphotoluminescence (mu PL) spectra of high-quality hBN/WS2/MoSe2/hBN heterostructures under perpendicular magnetic fields up to 20 T. We identify two neutral exciton peaks in the mu PL spectra; the lower-energy peak exhibits a reduced g-factor relative to that of the higher energy peak and much lower than the recently reported values for interlayer excitons in other van ...
Strain tunable interlayer and intralayer excitons in vertically stacked MoSe₂/WSe₂ heterobilayers Universiteit Antwerpen
Recently, interlayer and intralayer excitons in transition metal dichalcogenide heterobilayers have been studied both experimentally and theoretically. In spite of a growing interest, these layer-resolved excitons in the presence of external stimuli, such as strain, remain not fully understood. Here, using density-functional theory calculations with many-body effects, we explore the excitonic properties of vertically stacked MoSe2/WSe2 ...
Interlayer excitons in transition metal dichalcogenide heterostructures Universiteit Antwerpen
Starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs), we construct a four-band Hamiltonian describing interlayer excitons consisting of an electron in one TMD layer and a hole in the other TMD layer. An expression for the electron-hole interaction potential is derived, taking into account the effect of the dielectric environment above, below, and between the two TMD layers ...