Pressure effects on neutral and charged excitons in self-assembled InGaAs/GaAs quantum dots

Abstract

By combining an atomistic pseudopotential method with the configuration interaction approach, we predict the pressure dependence of the binding energies of neutral and charged excitons: $X^0$ (neutral monoexciton), $X^{-}$ and $X^{+}$ (charged trions), and $X{X}^0$ (biexciton) in lens-shaped, self-assembled In${}_{0.6}$Ga${}_{0.4}$As/GaAs quantum dots. We predict that (i) with applied pressure the binding energy of $X^0$ and $X^{+}$ increases and that of $X^{-}$ decreases, whereas the binding energy of $X{X}^0$ is nearly pressure independent. (ii) Correlations have a small effect in the binding energy of $X^0$, whereas they largely determine the binding energy of $X^{-}$, $X^{+}$ and $X{X}^0$. (iii) Correlations depend weakly on pressure; thus, the pressure dependence of the binding energies can be understood within the Hartree-Fock approximation and it is controlled by the pressure dependence of the direct Coulomb integrals $J$. Our results in (i) can thus be explained by noting that holes are more localized than electrons, so the Coulomb energies obey $J^{(hh)}>J^{(eh)}>J^{(ee)}$.

arXiv comment4+ pages, 2 figures

References in corpus (2)

• Comparison of two methods for describing the strain profiles in quantum dots
• Theoretical interpretation of the experimental electronic structure of lens shaped, self-assembled InAs/GaAs quantum dots

Cited by in corpus (3)

• Excitons, biexcitons and trions in self-assembled (In,Ga)As/GaAs quantum dots: Recombination energies, polarization and radiative lifetimes versus dot height
• Carrier relaxation mechanisms in self-assembled (In,Ga)As/GaAs quantum dots: Efficient P -> S Auger relaxation of electrons
• Biexciton recombination rates in self-assembled quantum dots