Linear and nonlinear optical properties of a superlattice with periodically increased well width under electric and magnetic fields
Date
14.04.2022Metadata
Show full item recordAbstract
In this paper, we have studied the electronic and optical properties of GaAs/AlxGa1-xAs superlattice
with periodically increased well width. Under effective mass approximation, the finite
element method is used to obtain wavefunctions and corresponding energy eigenvalues for
several electric field (F) and magnetic field (B) values. We have shown that the increasing well
width has a major effect on the localization of the first two energy states. The direction of the
applied electric field shifts the localization position of the probability density of electrons to the
left and right. For B = 0 (according to the parameters used), F = 5 kV/cm (especially for the
difference between the first two energy levels (E12)) is a critical value. While the E12 value decreases
in the range from 30 kV/cm to 5 kV/cm, it increases for the 5 < F < 30 kV/cm range.
This behavior causes a red or blue shift in the optical spectrum. Also, F = 30 kV/cm causes more
change in the structure than F = 30 kV/cm. In addition, the localization of the electrons is
observed in the center of the superlattice under applied magnetic fields. The optical absorption
coefficients and the refractive index changes are affected by applied F and B intensities. We can
say that the electro-optical features of the superlattice have changed significantly with the
combined effect of F and B values. This is desired for semiconductor optical device applications to
have stable performances.