1：Experimental Design and Method Selection:

The study employed co-sensitization approach using a ruthenium (II) based dye, N749, and an organic sensitizer, RK1. The solar cells were evaluated using UV–Vis spectroscopy, electrochemical impedance spectroscopy (EIS), incident photon to electron conversion efficiency (IPCE), and current-voltage (I-V) characteristics.

2：The solar cells were evaluated using UV–Vis spectroscopy, electrochemical impedance spectroscopy (EIS), incident photon to electron conversion efficiency (IPCE), and current-voltage (I-V) characteristics. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Two solutions of the individual dyes and five solutions of the mixtures of the dyes in ethanol were prepared at different concentrations.

3：List of Experimental Equipment and Materials:

Dyes (21822; Ruthenizer 620-1H3TBA, and 22751; Sensitizer RK1), electrolyte (35112; Iodolyte Z-50), anatase TiO2 paste (14412; T/SP), platinum paste (Plastisol T) and fluorine-doped tin oxide (SnO2:F) FTO conductive glass substrate, were obtained from Solaronix (Switzerland).

4：Experimental Procedures and Operational Workflow:

Tape casting was used to apply TiO2 paste on the FTO conductive glass substrates and it was annealed at 200 °C for the first 10 min and 450 °C for the next 20 min to fabricate the mesoporous scaffolding layer for photoanodes. The photoanodes were prepared by soaking the FTO conductive substrates deposited with TiO2 layer for 24 h into dye solutions. The platinum counter electrodes were also fabricated using platinum paste with similar tape casted on to the FTO glass substrates and annealing at 450 °C for 30 min.

5：Data Analysis Methods:

The performance of the fabricated DSSCs was characterized using UV–Vis spectroscopy, I-V characteristics determination, incident photon to electron conversion efficiency (IPCE), and EIS analysis.