1：Experimental Design and Method Selection:

The study employed pulsed laser deposition (PLD) to create a layer of B-doped p-type UNCD/a-C:H on a substrate of n-type Si(100) wafer. The methodology included the measurement of capacitance–voltage–frequency (C–V–f) and conductance–voltage–frequency (G–V–f) plots, and impedance spectroscopy to investigate electrical features.

2：Sample Selection and Data Sources:

The samples consisted of n-type Si/B-doped p-type UNCD heterojunction photodiodes. The carrier concentration value of

3：1 at.% B-doped UNCD/a-C:

H films was estimated to be around 6.1 × 10^15 cm^?

4：1 × 10^15 cm^?List of Experimental Equipment and Materials:

3. 3. List of Experimental Equipment and Materials: Equipment included a PLD apparatus, an ArF excimer laser, a radio-frequency magnetron sputtering apparatus, a Keithley 2400 series source meter, an Agilent E4980A Precision LCR Meter, and a Handy UV Lamp (AS ONE SLUV-6). Materials included a graphite target containing 0.1 at.% boron, Aluminium (Al), and Palladium (Pd) for Ohmic contacts.

5：6). Materials included a graphite target containing 1 at.% boron, Aluminium (Al), and Palladium (Pd) for Ohmic contacts. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The PLD process involved raising the substrate temperature to 550 °C, focusing a laser beam onto the B-doped graphite target, and creating Ohmic contacts of Al and Pd. The electrical characteristics were measured under dark and illumination conditions.

6：Data Analysis Methods:

The Nicollian-Brews approach was used to approximate Rs values, and the Hill-Coleman approach was applied to assess Nss values. Impedance spectroscopy was used to analyze the electrical characteristics.