This study investigates the optical and photovoltaic properties of monolithic dye-sensitized solar cells (DSSCs) utilizing Hibiscus sabdariffa dye extract as a natural sensitizer. Four distinct cell architectures were fabricated and systematically characterized: \({\textrm{TiO}}_2\) photoelectrodes, \({\textrm{TiO}}_2\) – \({\textrm{SnO}}_2\) core-shell structures, and coupled catalyst counter electrodes incorporating platinum-carbon and antimony sulfide-carbon configurations. Comprehensive optical characterization through UV–Vis spectroscopy revealed the absorption properties of the dye extract, mesoporous \({\textrm{TiO}}_2\) films, and dye-sensitized photoelectrodes. Under standard AM 1.5G illumination conditions, the monolithic DSSC with conventional \({\textrm{TiO}}_2\) photoelectrode demonstrated competitive photovoltaic performance, achieving a power conversion efficiency (PCE) of 2.7 ± 0.1% compared to 2.2 ± 0.1% for the \({\textrm{TiO}}_2\) – \({\textrm{SnO}}_2\) core-shell architecture. The incorporation of the \({\textrm{SnO}}_2\) shell, while theoretically favorable for electron transport, unexpectedly reduced performance, possibly due to interfacial resistance or defect-mediated recombination. These findings provide comparative data for natural dye-based monolithic DSSC architectures and highlight the viability of Hibiscus sabdariffa as a sustainable photosensitizer, while revealing that certain architectural modifications successful with synthetic dyes may not directly transfer to natural sensitizer systems.
