Influence of ZnO doping on the band gap energy of TiO2 thin films for solar energy applications

This study investigates the optical properties of ZnO-doped TiO2 thin films, focusing on the determination of their band gap energy (Eg) using the Kubelka-Munk method. The reflectance measurements were conducted over a wavelength range of 200-800 nm, revealing significant variations in light absorption capabilities depending on the amount of ZnO doping. The results indicated that the band gap energy for pure TiO2 was approximately 2.99 eV, while ZnO doping increased the band gap energy to 3.02 eV. This increase suggests that the incorporation of ZnO modifies the electronic structure of TiO2, enhancing its optical properties. The findings highlight the potential of ZnO-doped TiO2 thin films for improving the efficiency of Dye-Sensitized Solar Cells (DSSCs) by allowing for greater light absorption in the visible spectrum. This research contributes to the development of more efficient renewable energy technologies by optimizing semiconductor materials for photovoltaic applications.