1：Experimental Design and Method Selection:

The study employed electrodeposition technique to deposit Cu2O thin films on FTO glass substrates at different deposition potentials (-0.2 to -0.5 V) using a three-electrode cell system. The rationale was to tailor film properties by adjusting electrodeposition parameters.

2：2 to -5 V) using a three-electrode cell system. The rationale was to tailor film properties by adjusting electrodeposition parameters. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: FTO glass substrates were used, cleaned ultrasonically in acetone, isopropanol, and deionized water. The deposition solution contained 0.15 mol L?1 copper sulphate pentahydrate and 1 mol L?1 lactic acid with pH adjusted to 11 using NaOH.

3：15 mol L?1 copper sulphate pentahydrate and 1 mol L?1 lactic acid with pH adjusted to 11 using NaOH. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Potentiostat (Model 362, EC & G Princeton Applied Research), X-ray diffractometer (X'PERT PRO analytic), scanning electron microscope (ZEISS), micro-Raman spectroscopy system, photoluminescence spectrometer (RF-6000, SHIMADZU), UV-Vis-IR spectrometer (UV-1800, SHIMADZU), stylus profilometer, LCR meter, Keithley semiconductor characterization system 4200, Xenon lamp for illumination.

4：Experimental Procedures and Operational Workflow:

Films were deposited at 55°C for 30 minutes, rinsed in deionized water, and dried at 100°C. Structural analysis via XRD, morphological via SEM, vibrational via Raman, optical via UV-Vis and PL, electrical via LCR, and photoconductivity via I-V measurements under light illumination.

5：Data Analysis Methods:

Crystallite size calculated using Scherrer formula, micro-strain and dislocation density from XRD data, band gap from Tauc's plot, ac conductivity from dielectric measurements, and photoconductivity from I-V curves.