Computations of the optical transitions and absorption spectra in a set of realistic, elongated InAs/GaAs quantum boxes having a Gaussian distribution

Abstract

InAs/GaAs quantum dots (QDs) grown by various methods do not have the same dimensions in the three axes. This paper reports on expressions for computations of the optical transitions and absorption spectra of InAs/GaAs QDs that have a square base and the variation of the height is Gaussian. The dots were considered to be elongated quantum boxes with square bases having finite potentials at the boundaries. The results are in excellent agreement with reported experimental data of photoluminescence and absorption. The expressions could be successfully applied to short quantum wires.

Investigations on optical transitions in InAs/InP quantum dash structures

“…where E g is the band gap of the low band gap semiconductor material and l, m and n are all positive integers. E e (l 2 , m 2 , n 2 ) and E h (l 2 , m 2 , n 2 ) are the confinement energies of the electron and hole (in units of h 2 /mL 2 ) for a finite 3D rectangular well, respectively, as given by the following equations (Kabi et al 2011):…”

“…gðl 2 ;m 2 ;n 2 Þ is the degeneracy of the energy level determined by the values of (l, m, n). A real is a constant in terms of the momentum matrix P n (Kabi et al 2011). The interband absorption of a QDH is characterized by a series of discrete lines at photon energies given by Eq.…”

“…Using the properties of Dirac delta function, the relative absorption co-efficient is calculated as (Kabi et al 2011)…”

“…This paper addresses the nature of the absorption spectra from a family of InAs/InP QDHs for various depths and the standard deviation of the depth. The theoretical formulation is developed by considering the InAs/InP QDH as a quantum box (QB) characterized by a rectangular base and a finite potential at the barrier (Kabi et al 2011). We have studied different sets of QDH when the base length remains constant for various values of the relative standard deviation of the dash.…”

Efficiency of quantum dot solar cell enhanced by improving quantum dots performance

“…Here, we focus on getting a better match between the absorption spectrum of QDs and the spectral portions of the solar spectrum. The absorption spectrum has been investigated in terms of the dot volume, shape, materials, and the nonuniformity of dot size . However, the correlations between these issues used to enhance the conversion efficiency are still not fully revealed.…”