Fabrication and characterization of Al/glass zig-zag thin film, comparing to the discrete dipole approximation results

Abstract

Aluminum zig-zag thin film was coated on the glass substrate by the oblique angle deposition (OAD) method. X-ray diffraction (XRD) revealed the formation of cubic phase with the peak in the (111) plane. The field emission scanning electron microscopy (FESEM) analysis used to estimate the films thickness, columns magnitude and its shape. The unpolarized light absorption spectrum of the zig-zag Al thin film was obtained by spectroscopy analysis in 330–850 nm. Besides, the scattering and absorption spectra of these nanostructures were simulated by the discrete dipole approximation (DDA) and the results compared to the empirical data. The Al zig-zag thin film was simulated by an array of electric dipoles and optical spectra were obtained as function of azimuthal angles and arm lengths. The simulation results show that, at the zero degree incident angles for different azimuthal angles the peaks intensity increases by decreasing azimuthal angle. Besides, by increasing the arm lengths, the peak of shorter wavelength shifts toward the longer wavelengths and the peak of longer wavelength become sharper. From a general viewpoint, the observations had a good agreement to empirical data, nevertheless, the differences needs special attention.