Superlattice formed by quantum-dot sheets: density of states and IR absorption

TL;DR

This paper theoretically analyzes the electronic states and infrared absorption properties of a superlattice formed by periodically arranged quantum-dot sheets, revealing how these properties depend on structural parameters for optoelectronic applications.

Contribution

It introduces a theoretical model for the density of states and IR absorption in quantum-dot sheet superlattices, linking structural parameters to optical properties.

Findings

Density of states depends on dot concentration and sheet period.

Infrared absorption spectra are influenced by superlattice parameters.

Model can aid in characterizing multilayer quantum-dot structures.

Abstract

Low-energy continuous states of electron in heterosrtucture with periodically placed quantum-dot sheets are studied theoretically. The Green's function of electron is governed by the Dyson equation with the self-energy function which is determined the boundary conditions at quantum-dot sheets with weak damping in low-energy region. The parameters of superlattice formed by quantum-dot sheets are determined using of the short-range model of quantum dot. The density of states and spectral dependencies of the anisotropic absorption coefficient under mid-IR transitions from doped quantum dots into miniband states of superlattice strongly depend on dot concentration and on period of sheets. These dependencies can be used for characterization of the multi-layer structure and they determine parameters of different optoelectronic devices exploiting vertical transport of carriers through quantum-dot sheets.