1：Experimental Design and Method Selection:

The study fabricated two types of BP NC-FETs by connecting regular BP FETs to a negative capacitance capacitor made of HfZrO ferroelectric material. This approach was chosen to avoid interface effects and allow separate optimization of the FET and capacitor. Theoretical modeling based on the Landau-Khalatnikov equation and Poisson's equation was used to analyze the NC effect.

2：Sample Selection and Data Sources:

BP flakes were exfoliated on SiO2 substrates. The devices were fabricated and characterized electrically.

3：List of Experimental Equipment and Materials:

Atomic layer deposition (ALD) system for depositing AlOx and HfZrO films, e-beam lithography system for patterning, thermal evaporation system for metal deposition, sputtering system for TiN electrodes, transmission electron microscope (TEM) for imaging, and electrical measurement setups for polarization, capacitance, and transistor performance.

4：Experimental Procedures and Operational Workflow:

For type-I BP FET: exfoliate BP on SiO2, pattern source/drain contacts via e-beam lithography and thermal evaporation, deposit 30-nm AlOx by ALD, form top-gate electrode. For type-II BP FET: form Al metal on BP to self-form 5-nm AlOx, then exfoliate BP and form source/drain. For NC capacitor: sputter TiN bottom gate, deposit 20-nm HfZrO by ALD, deposit and pattern top TiN electrode, anneal. Connect FET to capacitor and measure electrical properties.

5：Data Analysis Methods:

Polarization measured using positive up negative down method, capacitance measured with small signal method, subthreshold slope extracted from transfer curves, and theoretical model fitted to experimental data using Landau coefficients.