The Electrical Conductivity in Superlattices of Spherical Quantum Dots

<p>We investigate the electrical properties of semiconductor spherical GaAs/AlxGa1-xAs quantum-dot systems of different dimensionality depending on the Fermi level position and temperature, and concentration of aluminum in the matrix. We obtained the dependences of electron group velocity on electron miniband index. Decreasing of the quantum dot radius as well as increasing of aluminum concentration in the matrix leads to rising of group velocity. The group-velocity sign change is caused by the behavior of equipotential surfaces of these minibands. We calculated the conductivity which contains contributions of s- and three p-minibands at given parameters of the system. Its maximum is located near the miniband center. The increase of electrical conductivity is observed with reducing of quantum-dot radius and aluminum concentration and also with decreasing of dimensionality of the GaAs/AlxGa1-xAs superlattice. We also investigated the temperature dependence of electrical conductivity at various parameters of these systems.</p><p>Keywords: quantum dot, superlattice, electronic states, density of states, electrical conductivity.</p>