Fabrication and Characterization of Co and Li Doped TiO2 Photoanodes for High-Efficiency Dye-Sensitized Solar Cells

Abstract

The urgent need for a sustainable energy future has driven global efforts to transition from fossil fuels to renewable energy sources. However, challenges such as escalating energy demands, environmental degradation, and the accelerating climate crisis hinder this transition. Dye-sensitized solar cells (DSSCs) emerge as a promising alternative, offering potential advantages like affordability, flexibility, and enhanced efficiency. Titanium (IV) Oxide (TiO2), a widely studied semiconductor material, has been extensively explored for DSSC applications. However, its inherent limitations, including a wide bandgap, significant charge recombination losses, and low electrical conductivity, impede the development of efficient and cost-effective DSSCs. This study aims to address these challenges and contribute to the advancement of DSSC technology as a viable and sustainable energy solution. DSSCs were fabricated using TiO2 photoanodes doped with cobalt (Co) and lithium (Li) via a one-pot sol-gel synthesis approach. Ruthenium-based dye N719 was utilized as the sensitizer. Characterization techniques, including XRD, FTIR, DRS, FESEM, and EDX, were employed to analyze the structural, optical, morphological, and elemental properties of the synthesized materials. Doping with Co and Li effectively reduced the TiO2 bandgap from 3.18 eV to 3.12 eV and 2.88 eV, respectively, leading to enhanced short-circuit current density (Jsc) values of 10.97 mA/cm² and 12.37 mA/cm², respectively. Among the fabricated DSSCs, the Li-doped TiO2 photoanode demonstrated the highest power conversion efficiency of 5.3%, followed by Co-doped TiO2 (4.2%) and undoped TiO2 (3.3%). These findings highlight the potential of Li and Co-doped TiO2 as promising materials for the development of high-performance DSSCs.