1：Experimental Design and Method Selection:

The electrodeposition method was used to fabricate undoped and Pr-doped Cu2O nanocrystalline films. A three-electrode system was employed with FTO as the working electrode, platinum wire and Ag/AgCl as electrodes. The deposition potential was fixed at -400 mV vs. SCE for 30 minutes at room temperature, with pH adjusted to 13 using NaOH. Pr doping was achieved by adding PrCl3·6H2O to the copper precursor solution.

2：Sample Selection and Data Sources:

Films were prepared with Pr doping concentrations of 0, 1, 3, and 5 wt%. FTO-coated glass substrates were used, cleaned ultrasonically in ethanol and acetone.

3：List of Experimental Equipment and Materials:

Equipment included X-ray diffractometer (XRD) with CuKα radiation, Raman system (Princeton Acton SP-2500), scanning electron microscope (EVO18 ZEISS), stylus profilometer, UV–vis–NIR spectrometer (Lambda Perkin Elmer), photoluminescence spectrometer (Perkin Elmer LS55), and Keithley source meter (2450 model) with halogen lamp. Materials included copper sulfate, lactic acid, NaOH, PrCl3·6H2O, FTO substrates, platinum wire, and Ag/AgCl electrode.

4：Experimental Procedures and Operational Workflow:

The electrodeposition process involved preparing a copper complex solution, adjusting pH, and depositing films at fixed potential. Post-deposition, films were characterized for structure (XRD, Raman), morphology (SEM, EDAX), thickness (stylus profilometer), optical properties (UV–vis–NIR, PL), and electrical properties (I–V measurements under dark and illuminated conditions).

5：Data Analysis Methods:

Structural parameters were analyzed using Scherer formula for crystallite size, microstrain, dislocation density, texture coefficient, and lattice constants. Optical band gap was calculated using Tauc’s plot. Refractive index, extinction coefficient, and dielectric constants were derived from reflectance and absorption data. I–V curves were analyzed for photoresponse behavior.