Evaluation of titania-based thin films fabricated via the aqueous spray method for applications as anti-soiling coatings on solar cell cover glass

A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Renewable Energy

The growing demand for sustainable energy has made solar energy essential in the world energy transition. To maximize power output, solar PV systems must operate effectively. However, factors like soiling on the solar cell cover can reduce efficiency and overall power output. Traditional cleaning methods are typically expensive and labor-intensive, therefore emphasizing the need for simpler, cost-effective solutions like anti-soiling coatings. This study investigates the structural, optical, and photocatalytic properties of aluminum (Al), zinc (Zn), and copper (Cu) doped titanium dioxide (TiO₂) thin films prepared via an aqueous spray method. Aqueous precursor solutions were formulated by mixing Ti⁴⁺ complexes with Al³⁺, Zn²⁺, or Cu²⁺ complexes, with molar percentages varying from 0% to 10%. The results from UV-vis spectroscopy indicated that doping significantly enhanced the optical properties of TiO₂ thin films, with Al, Zn, and Cu-doped films showing higher transmittance than undoped TiO₂. X-ray diffraction (XRD) confirmed that all samples retained the anatase phase of TiO₂ without secondary phases of the dopants. Photocatalytic degradation tests revealed that 6% Cu-doped TiO₂ exhibited the highest degradation rate of 28% for methyl orange (MO), while 8% Al-doped and 2% Zn-doped films showed optimal activity at their respective levels. These findings suggest that doping TiO₂ thin films at appropriate doping concentrations can enhance their optical properties and photocatalytic efficiency, making them promising candidates for anti-soiling applications on solar cell covers