1：Experimental Design and Method Selection:

The study involved fabricating Au/n-Si metal–semiconductor structures with a 2% graphene cobalt-doped (Ca3Co4Ga0.001Ox) interlayer. Electrical and dielectric properties were analyzed using capacitance/conductance–voltage (C/G–V) measurements in the frequency range of 5–500 kHz at room temperature. Methods included the low–high-frequency capacitance method for interface states (Nss) extraction and the Nicollian–Brews method for resistance (Ri) extraction. Complex dielectric constant, electric modulus, and ac conductivity were calculated from C and G data.

2：001Ox) interlayer. Electrical and dielectric properties were analyzed using capacitance/conductance–voltage (C/G–V) measurements in the frequency range of 5–500 kHz at room temperature. Methods included the low–high-frequency capacitance method for interface states (Nss) extraction and the Nicollian–Brews method for resistance (Ri) extraction. Complex dielectric constant, electric modulus, and ac conductivity were calculated from C and G data. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: P-doped single-crystal n-Si wafers with resistivity of 0.001–0.005 Ω·cm, 250-μm thickness, and (100) orientation were used. The interlayer was synthesized via sol–gel method and deposited by electrospinning. High-purity Au was used for contacts.

3：001–005 Ω·cm, 250-μm thickness, and (100) orientation were used. The interlayer was synthesized via sol–gel method and deposited by electrospinning. High-purity Au was used for contacts. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included an HP 4192A LF impedance analyzer for C–V and G/ω–V measurements, a metal evaporation system for Au deposition, a quartz crystal thickness monitor, an ultrasonic bath for cleaning, and a microcomputer with IEEE-488 ac/dc converter card. Materials included n-Si wafers, Au (99.999% purity), Ca3Co4Ga0.001Ox doped with 2% graphene cobalt, polyvinyl alcohol polymer, deionized water, and various chemical solutions for cleaning.

4：999% purity), Ca3Co4Ga001Ox doped with 2% graphene cobalt, polyvinyl alcohol polymer, deionized water, and various chemical solutions for cleaning. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The n-Si wafer was cleaned chemically and with deionized water, dried with nitrogen gas. Ohmic back contact was formed by evaporating Au and annealing at 500°C in nitrogen. The interlayer was grown by electrospinning on the front surface. Au dots (1500 ? thickness, 1 mm diameter) were deposited on the interlayer. C–V and G/ω–V measurements were performed at frequencies from 5 to 500 kHz with a 40 mV sinusoidal test signal.

5：Data Analysis Methods:

Data analysis involved extracting Nss and Ri from C and G data, calculating ε', ε'', M', M'', and σac using standard formulas. Frequency and voltage dependencies were analyzed to understand conduction mechanisms and polarization effects.