Baric properties of InAs quantum dots

Abstract

-In the context of the deformation potential model, baric dependences of the energy structure of InAs quantum dots in a GaAs matrix are calculated. Under the assumption of the absence of interaction between the spherical quantum dots of identical sizes, the energy dependence of the baric coefficient of energy of the radiative transition in the quantum dot is determined. A similar dependence is also found experimentally in the photoluminescence spectra under uniform compression of the InAs/GaAs structures. Qualitative agreement between the theory and experiment as well as possible causes for their quantitative difference are discussed. It is concluded that such factors as the size dispersion, Coulomb interaction of charge carriers, and tunnel interaction of quantum dots contribute to this difference.

Polaron State in the Self-Consistent Electron-Deformation Field of the Quantum Dot-Matrix System

“…where u(r) is the atomic displacement in the QD material, which should satisfy the following boundary conditions [13][14][15]:…”

Influence of Electron-Deformation Effects on the Electron Structure of Quantum Dots in Stressed Nanoheterosystems

“…Substituting the expressions obtained for the components of the mechanical and electron strain tensors (6)- (11) and expressions (20) and (21) for the electrostatic potential into formula (1), we obtain a formula for the potential energy of an electron in the stressed nanoheterosystem with quantum dots that involves the self-consistent electron-deformation interaction.…”

“…The optical and electronic properties of quasi-zerodimensional structures are governed, to a great extent, by the energy spectrum of spatially confined electrons and holes, which was calculated both making no allowance for the mechanical component of a deformation [5,6] and making allowance for it in the framework of a rectangular quantizing potential [7][8][9][10][11]. The corresponding models considered the influence of a self-consistent deformation of the crystal matrix and QDs, the Laplace pressure at the QDmatrix interface, the finite size of the surrounding matrix, and the dependence of the parameter describing the mismatch between the contacting lattices at their heterointerface on the dimensions of a QD and the matrix.…”

Electric properties of the interface quantum dot - matrix

“…Therefore, the energy of the ground state of the electron in the QD is determined from the following transcendental equation [9]:…”

“…In order to reduce the problem with a large number of QDs to the problem with one QD, we use the following approximation. The energy of the pairwise elastic interaction between the QDs can be replaced by the energy of interaction of each QD with the averaged elastic strain field σ ef (N − 1) of all other (N − 1) QDs [9]. Thus, QD InAs in matrix n-GaAs creates a potential well for electrons, and in p-GaAs -a potential well for holes, accordingly (see figure 1).…”