1：Experimental Design and Method Selection:

ZnSx nanoparticles with different sulfur ratios (x =

2：5, 1, and 2) were prepared using the solvothermal technique. The structural, morphological, and optical properties were characterized using XRD, SEM, FTIR, TGA, and UV-Vis spectroscopy. The nanoparticles were then used to fabricate dye-sensitized solar cells (DSSCs) via spin coating. Sample Selection and Data Sources:

Zinc acetate dihydrate and thiourea were used as starting materials, with ethanol as the solvent and diethanolamine as the stabilizer.

3：List of Experimental Equipment and Materials:

Equipment included a Teflon-lined stainless steel autoclave, spin coater (VTC-100 vacuum spin coater), ultrasonic cleaner (Bransonic 1210 USA), XRD (Shimadzu XD-6000), SEM (Quanta 250 FEG), FTIR (Bruker-Vertex 70), TGA (Shimadzu-50), UV-Vis spectrophotometer (Shimadzu UV-160A), and γ-irradiation source (Cobalt-60 Indian Gamma cell GC 4000A).

4：Experimental Procedures and Operational Workflow:

The solvothermal process involved stirring zinc acetate dihydrate in ethanol, adding thiourea, and heating in an autoclave. The resulting nanoparticles were centrifuged, washed, dried, and then spin-coated onto FTO glass substrates. The DSSCs were assembled and their I-V characteristics measured under illumination and in dark.

5：Data Analysis Methods:

The optical band gap was calculated from absorbance measurements using the Beer-Lambert relation and Tauc plot. The crystallite size was determined using the Debye-Scherrer formula.