Review of self-cleaning TiO₂ thin films deposited with spin coating

This paper reviewed the deposition of thin films of TiO₂ for self-cleaning applications deposited using the spin coater. The overwhelming global demand for electricity pushes power producers to develop substitute energy sources. Renewable energy sources such as solar, wind, tidal, geothermal, and hydroelectric are now considered to create alternative power sources. The most abundant form on earth is solar energy, converted to electrical energy using a solar panel. Regrettably, solar panels attract contaminants once exposed to the atmosphere, causing their efficiency to drop. Self-cleaning is one of the researched technologies to help maintain clean photovoltaic surfaces. Titanium dioxide (TiO₂) is among the materials studied for self-cleaning, and the spin-coating method offers great promise. This paper presented the background and working principle of the spin coater, precautions to be taken with the spin-coating process, and the merits and demerits of the process. The paper highlighted the self-cleaning mechanism and the spin-coating method to create self-cleaning TiO₂ thin films for application on several surfaces, including the solar panel. Commonly used self-cleaning materials were also reviewed, including materials used to dope or create TiO₂ composite for better self-cleaning capability. Effects of process parameters, available substrates, surfactants, solvents, and stabilizing agents on the final TiO₂ thin film performance and recent innovative efforts to improve the spin-coating process and the self-cleaning abilities of TiO₂ are reviewed. This will contribute to the body of knowledge on spin-coating techniques, self-cleaning thin films, and TiO₂.