Development of a single-layer TiO2 photoanode for DSSCs with structural and photovoltaic analysis

The performance of dye-sensitized solar cells (DSSCs) is strongly governed by the structural integrity, charge transport properties, and recombination behavior of the TiO 2 photoanode. Although single-layer and double-layer TiO 2 photoanode architectures have been widely investigated, the relationship between internal structural defects, thickness non-uniformity, and photovoltaic performance in simplified single-layer DSSCs remains insufficiently clarified. In this work, a single-layer mesoporous TiO 2 photoanode was fabricated using a controlled deposition method and systematically investigated by combining morphological observation, non-destructive X-ray microtomography, electrochemical analysis, and photovoltaic measurements. X-ray microtomography enabled the visualization of internal pore-type defects, agglomerates, and local thickness variations that cannot be fully identified by conventional surface-sensitive characterization techniques. These structural features were correlated with charge transport pathways, recombination behavior at the TiO 2 /dye/electrolyte interface, and the resulting photovoltaic parameters of the assembled DSSCs. The results show that improved structural uniformity in the single-layer TiO 2 photoanode facilitates more continuous electron transport and contributes to reduced recombination losses. The study demonstrates that the performance of simplified single-layer DSSCs is determined not only by photoanode architecture, but also by internal defect distribution and thickness uniformity. Therefore, the main contribution of this work is the combined structural–electrochemical–photovoltaic analysis of a single-layer TiO 2 photoanode rather than the mere fabrication of a single-layer DSSC architecture