INVESTIGATION OF INTENSE PULSED HIGH-CURRENT ION BEAM INTERACTION WITH ITO AND FTO COATINGS

Abstract

This master’s thesis investigates the effect of irradiation of intense pulsed ion beam (IPIB) on transparent oxides such as FTO (Fluorine-doped Tin Oxide) and ITO (Indium Tin Oxide), and focuses on their structural, optical, and electrical characteristics. Research was carried out as part of INURA (Innovative Nazarbayev University’s Research Accelerator) Accelerator Lab research activity on the application of a pulsed high-current ion beam with a nanosecond pulse duration to modify materials that possess a variety of functional properties, such as flexible transparent conductors, photocatalysts, plasmonic nanoparticles, and solar cells where commercial FTO and ITO substrates are widely used. Generally, FTO and ITO coatings, as transparent conductive oxide (TCO), play a vital role in the electronics industry. Their transparency while conducting electrical current makes them valuable components in various applications, including photovoltaic cells, touchscreens, and electrochromic device windows. This thesis is focused on investigating the radiation resistance of FTO and ITO substrates under exposure to intense pulsed ion beams (IPIB) within the current density range typically used for nanomaterial modification. In this research, commercial FTO and ITO thin films were exposed to intense pulsed ion beam (IPIB) effects on their crystal structure, electrical conductivity, and optical transmission. The results show that the glass-based FTOs have high radiation resistance to IPIB at ion beam current densities of up to 18 A/cm2, which is reflected in the preservation of transparency and sheet resistance. A novel experimental approach in surface-enhanced Raman scattering (SERS) substrate fabrication has been developed. FTO substrates coated with a 3 nm layer of gold were irradiated with IPIB, causing the formation of gold-plasmonic nanoparticles. As a result, the Raman signal of a low-concentration methylene blue solution (10⁻⁵ M) was enhanced. The samples were characterized using AFM, SEM, UV-Vis absorption spectroscopy, XRD, and Raman spectroscopy to evaluate the amplification of Raman signals resulting from the SERS effect.