Tight-binding calculations of image charge effects in colloidal nanoscale platelets of CdSe

International audienceCdSe nanoplatelets show perfectly quantized thicknesses of few monolayers. They present a situation of extreme, yet well de ned quantum con nement. Due to large dielectric contrast between the semiconductor and its ligand environment, interaction between carriers and their dielectric images strongly renormalize bare single particle states. We discuss the electronic properties of this original system in an advanced tight-binding model, and show that Coulomb interactions, including self-energy corrections and enhanced electron-hole interaction, lead to exciton binding energies up to several hundred meVs

Local wavefunction and exciton fine structure in extended-basis tight binding model

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Microscopic electronic wave function and interactions between quasiparticles in empirical tight-binding theory

International audienceA procedure to obtain single-electron wave functions within the tight-binding formalism is proposed. It is based on linear combinations of Slater-type orbitals whose screening coefficients are extracted from the optical matrix elements of the tight-binding Hamiltonian. Bloch functions obtained for zinc-blende semiconductors in the extended-basis spds∗ tight-binding model demonstrate very good agreement with first-principles wave functions. We apply this method to the calculation of the electron-hole exchange interaction, and obtain the dispersion of excitonic fine structure in bulk GaAs. Beyond semiconductor nanostructures, this work is a fundamental step toward modeling many-body effects from post-processing single-particle wave functions within the tight-binding theory

Self-energy driven exciton binding energy in II-VI semiconductor nanoplatelets

International audienceSelf-energy driven exciton binding energy in II-VI semiconductor nanoplatelet

Excitonic properties of II-VI semiconductor colloïdal nanoplatelets

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Dielectric Confinement in Layered II-VI Semiconductor Colloidal Nanoplatelets and Hybrid Perovskites

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