Study of the Effect of Thickness on the Optical Properties of MnBi0.95Sb0.05 Thin Film

Abstract

MnBi0.95Sb0.05 alloys were prepared by the conventional melt technique and then deposited as a thin film by thermal evaporation technique with different thicknesses. The optical absorption, reflection, and transmission spectra of thin films were measured in the wavelength range of 250 nm to 2500 nm. In our work, MnBi0.95Sb0.05 thin films have a hexagonal structure (P63/mmc group). The optical properties are characterized by high absorption and reflection, as well as very low transmission. Besides that, the absorbance of MnBi0.95Sb0.05 films decreased with increasing thickness. The calculated energy gap of MnBi0.95Sb0.05 thin films depended on the film thickness. It decreases from 1.36V to 1.03V by increasing the thickness from 25nm to 75nm. Different optical parameters like n, k, and ϭopt are examined and discussed.

Isotropic and Anisotropic Complex Refractive Index of PEDOT:PSS

“…The influence of the thickness on the optical properties of thin films has been discussed previously in other works [ 41 ]. Some authors reported that the refractive index increased with increasing thickness (as found herein for the isotropic samples), due to an increase in the film density, as described in [ 42 ] for Al 2 O 3 .…”

“…In contrast, Han et al [ 43 ] reported that n increased for thicknesses below 40–65 nm in polymers such as poly(2-vinyl pyridine) (P2VP), poly(methyl methacrylate) (PMMA), and polystyrene (PS) due to film inhomogeneities associated with non-uniform polarizability. Analogously, a drop in n of MgF [ 15 ] and in k of MnBi 0.95 Sb 0.05 [ 41 ] was described. Other works showed the change in n with the film thickness, but no monotonic increasing or decreasing trend was found.…”