on the characteristics and optical properties of mn-based (mno2) helical conical nanostructure thin films

Mn-based helical conical nano-sculptured thin films were fabricated by means of oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different pitches of each revolution. atomic force microscopy, field emission scanning electron microscopy and x-ray diffraction (xrd) analyses were used to obtain morphology, nanostructure and crystallography of the samples. formation of mno2 film by the proposed method of this work is confirmed by the xrd results. optical spectra of the films were obtained using s- and p-polarized incident lights at three different incident light angles of 0°, 20° and 30°. bruggeman homogenization method was employed to obtain spectra for different optical parameters. the observed peaks/oscillations in these spectra are related to the different radii of the deposited sculptured structure with helical conical shape. results show that by engineering of mn-based (mno2) helical conical sculptured thin film the absorption is increased. hence, by engineering of this type of thin films the absorption increases due to entrapment of light between the elements of the structure (rings) and results in a high broadband absorption.