Computational study of carbon-doped TiO2(B) nanomaterials for improved dye-sensitized solar cells

Abstract

Surface doping has emerged as a promising approach to enhance the reactivity and optoelectronic properties of titanium dioxide (TiO2) and other inorganic oxide semiconductors. This strategy has significant potential to improve the efficiency and long-term stability of dye-sensitized solar cells (DSSCs). The present study employs density functional theory (DFT) calculations to investigate, for the first time, the adsorption behavior of the organometallic N719 dye on pristine and carbondoped ultrathin TiO2(B) films. Initially, the interaction between the N719 dye and the pristine TiO2(B) (100) surface is examined, considering various molecular orientations and anchoring configurations. The adsorption energies and the resultant changes in the semiconductor’s electronic structure are determined. Subsequently, the impact of carbon doping on the preferential adsorption configurations is analyzed. The results reveal that the adsorption of the N719 dye is energetically favorable on both the pristine and C-doped TiO2(B) (100) surfaces. Notably, all adsorption-related properties are significantly enhanced after carbon doping, with the adsorption energy increasing by up to 300% compared to the undoped surface. This substantial increase in adsorption performance is critical for achieving highly efficient and long-lasting DSSCs.