1：Experimental Design and Method Selection:

Electrochemical etching was used to prepare porous silicon layers from p-type Si, with parameters varied to control porosity and pore size. Current-voltage (I-V) characteristics were measured to assess electrical behavior in N2 gas.

2：Sample Selection and Data Sources:

p-type Si wafers (boron-doped, 1.4-2.6 Ωcm resistivity, (100) oriented) were used. Samples were prepared with different current densities, etching times, electrolyte concentrations, and anodization lengths as specified in Table

3：4-6 Ωcm resistivity, (100) oriented) were used. Samples were prepared with different current densities, etching times, electrolyte concentrations, and anodization lengths as specified in Table List of Experimental Equipment and Materials:

1. 3. List of Experimental Equipment and Materials: Equipment includes a Keithley 610C electrometer for current measurements, high vacuum evaporation system for depositing Al and Au layers, Hg lamp for photoluminescence (PL) measurements, and a gas exposure chamber. Materials include HF (40 Wt. %), ethanol (99.8 Wt. %), H2O, p-type Si wafers, Al, and Au.

4：8 Wt. %), H2O, p-type Si wafers, Al, and Au. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Si wafers were electrochemically etched in HF/ethanol/H2O solutions at specified parameters. After etching, samples were rinsed and dried. Au layers (20 nm) were deposited for electrical contacts. I-V measurements were conducted in air and N2 gas environments at room temperature and atmospheric pressure using a two-terminal sandwich configuration.

5：Data Analysis Methods:

I-V curves were analyzed to observe changes in conductivity. Porosity was calculated gravimetrically. PL spectroscopy was used to measure band gap energy.