1：Experimental Design and Method Selection:

The study involved the preparation of VONc/n-Si heterojunction by vacuum deposition of VONc compound onto n-Si single crystals. The structural analysis was performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrical and optoelectronic properties were investigated through current density-voltage (J-V) and capacitance-voltage (C-V) measurements under dark and illumination conditions.

2：Sample Selection and Data Sources:

VONc powder was purchased from Sigma Aldrich. n-Si substrates were used after removing natural oxide impurities by chemical etching.

3：List of Experimental Equipment and Materials:

Equipment included a thermal vacuum evaporator (HHV Auto 306), SEM (Philips XL30), XRD (Philips X'Pert), Keithley 2635A source-meter, and a C-V meter model 4108. Materials included VONc powder and n-Si substrates.

4：Materials included VONc powder and n-Si substrates. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The VONc film was deposited onto n-Si substrates under vacuum. The thickness was monitored using a quartz crystal sensor. The active area of the cell was 0.2 cm2. J-V and C-V measurements were conducted at various temperatures and under illumination.

5：2 cmJ-V and C-V measurements were conducted at various temperatures and under illumination. Data Analysis Methods:

5. Data Analysis Methods: The data were analyzed to determine the conduction mechanisms, built-in voltage, and photovoltaic parameters such as open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency.