Condensed Matter Physics, 2017, vol. 20, No. 2, 23704
DOI:10.5488/CMP.20.23704           arXiv:1706.07288

Title: Light absorption coefficient of an ordered array of spherical quantum dot chains
Author(s):
  V.I. Boichuk (Department of Theoretical and Applied Physics & Computer Simulation, Ivan Franko Drohobych Pedagogical University, 24 Ivan Franko St., 82100 Drohobych, Ukraine) ,
  I.V. Bilynskyi (Department of Theoretical and Applied Physics & Computer Simulation, Ivan Franko Drohobych Pedagogical University, 24 Ivan Franko St., 82100 Drohobych, Ukraine) ,
  R.I. Pazyuk (Department of Theoretical and Applied Physics & Computer Simulation, Ivan Franko Drohobych Pedagogical University, 24 Ivan Franko St., 82100 Drohobych, Ukraine)

We considered intersubband electron transitions in an array of one-dimensional chains of spherical quantum dots in the GaAs/AlxGa1-xAs semiconductor system. The absorption coefficient caused by these transitions was calculated depending on frequency and polarization of incident light and on Fermi level position, and temperature. We established the existence of two maxima of the absorption coefficient at the edges of the absorption band. It is shown that the absorption coefficient reaches its maximal value at the center of the region between the s-, p-like subbands and slightly varies with temperature. The change of the direction of the linearly polarized light wave incident on the chains from perpendicular to parallel leads to a sharp narrowing of the absorption band. It is obtained that the absorption bandwidth increases with the reduction of the quantum dot radius. We also analyzed the dependence of the absorption coefficient of GaAs/AlxGa1-xAs superlattice on concentration of aluminium in the matrix.

Key words: quantum dot, superlattice, electronic states, density of states, absorption coefficient
PACS: 73.21.Cd, 78.67.Pt


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