Self-consistent Coulomb effects and charge distribution of quantum dot arrays

Abstract

This paper considers the self-consistent Coulomb interaction within arrays of self-assembled InAs quantum dots (QDs) which are embedded in a pn structure. Strong emphasis is being put on the statistical occupation of the electronic QD states which has to be solved self-consistently with the actual three-dimensional potential distribution. A model which is based on a Green's function formalism including screening effects is used to calculate the interaction of QD carriers within an array of QDs, where screening due to the inhomogeneous bulk charge distribution is taken into acount. We apply our model to simulate capacitance-voltage (CV) characteristics of a pn structure with embedded QDs. Different size distributions of QDs and ensembles of spatially perodic and randomly distributed arrays of QDs are investigated.

Charge order in an interacting monolayer under transverse bias

“…Our model is similar to the one studied by Kießlich et al [37] and by Wetzler et al [38], but their systems were relatively small or disordered. Their focus was on small arrays of quantum dots in semiconductor heterostructures, while we are interested in the statistical physics of clean systems in the thermodynamic limit.…”

Coulomb‐mediated electron bunching in tunneling through coupled quantum dots

“…For ground states of InAs QDs in an GaAs matrix U ≈ 20 meV was determined by capacitance spectroscopy [24] and U should be even higher for an AlAs matrix due to the smaller size of the dots. However, the highly-doped contacts are close to the QD layer (a few nm) so that screening effects will reduce the Coulomb matrix elements [25].…”

Coulomb scattering with remote continuum states in quantum dot devices

“…For the induced potential U ind originating from the induced electron density δn 2D (q) in the quantum well layer the Fourier components of the three-dimensional Poisson equation [16] read as…”

“…The depletion of the wetting layer density by an electric field [13] has been shown to reduce the relaxation rates. Similarly, the electron density in the vicinity of the QDs is reduced in a pn diode by the depletion layer within a DLTS experiment [14,15,16]. Electrons which are candidates for a Coulomb scattering process are not located at the QDs anymore, but at some distance.…”