Photoionization cross section of donor single dopant in multilayer quantum dots under pressure and temperature effects
Abstract
The shallow donor single dopant confined in the multilayer cylindrical quantum dots is investigated numerically
within the framework of effective-mass approximation. The Schr¨odinger equation that governs the wave function
of a complicated system is solved numerically by the finite element method using the Python programming
language. The results indicate that the photoionization cross section (PCS) is similar to the Gauss function curve,
the height of the curve’s peak is proportional to oscillator strength, and the center peak position is related to the
impurity binding energy. These two last parameters are dependent on the distribution of probability density
across each part of the system. The probability density is tuned by the electron confinement and optical transition.
The augmentation of dot radius or temperature decreases the electron confinement, which causes a
redshift of PCS, and the presence of hydrostatic pressure blue shifts the PCS. On the other side, As the dot radius
and hydrostatic pressure are increased, the oscillator’s strength increases, raising values near the critical energy,
and vice versa for temperature.