An enhancement of absorption in monolayer graphene-based random photonic crystal by using a differential evolution optimization algorithm

In this article, we optimized thickness layers in a 1-D photonic crystal for getting maximum absorption by using a differential evolution algorithm. The results demonstrate that the optimized structure provides an absorption peak centered at
$125\ \mu \mathrm{m}$
with a value of 0.9. The absorption behavior of described configuration is calculated with the aid of the
$4\times 4$
characteristic matrix technique. Further, we also examined the impact of Fermi-level on absorption behavior. The findings revealed that an increase of Fermi-level value to −0.65 eV resulted in a unity absorption. In addition, we also surveyed the effect of the thickness of the silicon carbide layer on the absorption characteristics of the optimized structure. the results illustrate that the absorption peak wavelength shifted to
$125, 135,145\ \mu \mathrm{m}$
when its thickness varied from 3, 6, and
$9\ \mu \mathrm{m}$
respectively. It has applications in the design of tunable absorbers. Finally, we explored how the exterior magnetic field affected the absorption spectra. The findings show that applying
$\mathrm{B}=4\ \mathrm{T}$
enhances the absorption peak value to unity and expands its FWHM. This has application in the design of tunable sensors, absorbers, and photodetectors.