Exploring the role of rare earth elements doped TiO₂ based photoanodes on the performance of dye-sensitized solar cells

This study investigates the synthesis and characterization of rare earth elements (REEs) doped TiO₂ thin films based photoanodes for use in dye-sensitized solar cells (DSSCs). For this purpose, TiO₂ films were doped with Ho³⁺, La³⁺, Er³⁺, and Yb³⁺ ions to enhance photoelectrochemical properties. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy, BET surface area analysis, and X-ray photoelectron spectroscopy (XPS) were employed for the structural, morphological, and optical characterization of the synthesized photoanodes and CEs. REEs doping improved the surface morphology and optical properties of TiO₂, in particular, it increased photon absorption in the visible light range. La³⁺ and Ho³⁺ significantly improved photovoltaic performance, achieving power conversion efficiencies of 3.78% and 2.87%, respectively, compared to that of pure TiO₂. These enhancements indicate improved charge transport and light harvesting due to incorporation of REEs. Additionally, replacing the conventional platinum counter electrode (CE) with reduced graphene oxide (rGO) further enhanced performance, offering a low-cost and efficient alternative. The study highlights the combined benefits of REEs doping and rGO integration in improving DSSCs efficiency. These findings contribute to the development of more sustainable, cost-effective solar energy technologies and underline the potential of REEs-doped TiO₂ films and rGO electrodes in advancing next-generation photovoltaic devices.