Characterization broadband omnidirectional antireflection ITO nanorod films coating

Abstract

Three-dimensional (3D) nanostructure electrode based on the transparent conductive oxide (TCO) is an alternative and effective approach for increasing the performance of next-generation photovoltaic and optoelectronic devices. In this work, we prepared the vertically aligned indium tin oxide nanorods (ITO-NRs) film on silicon (100) wafer and commercial ITO thin-film coated glass substrate (ITO-TF/glass) by the glancing angle deposition (GLAD) technique. The morphologies of the ITO-NRs films were confirmed by field-emission scanning electron microscope (FE-SEM). The grazing-incident X-ray diffraction (GIXRD) observed that the ITO-NRs were formed as amorphous and nanocrystalline phase. The photoemission spectra revealed the atomic percentage of elements in ITO-NRs, and the work function of the ITO-NRs was found to increase as a function of layer thickness. To simply demonstrate their feasibility in TCO applications, the ITO-NRs films were deposited on ITO-TF/glass. We found that the resistivity of ITO-NRs on ITO-TF/glass was higher than that of a bare ITO-TF/glass substrate, which can explain through the surface recombination loss. Besides, by precisely tunning the layer thickness of ITO-NRs films, the optical transmittance was enhanced at 85.5–90.0% over the broad wavelength in the visible region with omnidirectional AR characteristic which is superior to that in conventional ITO-TF/glass. Our thickness dependence of the ITO-NRs properties discloses promising 3D TCO nanostructure in wide application.