Blue and black phosphorene on metal substrates: a density functional theory study

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Phosphorene, a 2D allotrope of phosphorus, exhibits unique electronic and optical properties.
• Controlling the synthesis of phosphorene polymorphs (blue and black) on suitable substrates is crucial for device applications.

Purpose of the Study:

• To investigate the energetic favorability and stability of blue phosphorene and black phosphorene on various metal substrates using first-principles calculations.
• To identify promising metal substrates for the efficient synthesis and exfoliation of blue and black phosphorene.

Main Methods:

• Density functional theory (DFT) calculations were employed to study 36 combinations of phosphorene (blue and black) overlayers on different metal surfaces.
• Calculations included formation energy (E_F), change in free energy per unit area (ΔΩ), and overlayer-substrate binding energy (E_b).

Main Results:

• All 36 overlayer-substrate combinations were found to be energetically favorable (negative formation energy).
• Ag(111), Al(110), Cu(111), Cu(110), and potentially Au(110) surfaces are identified as suitable for blue phosphorene synthesis.
• Ag(110) and Al(111) surfaces are identified as suitable for black phosphorene synthesis.
• Charge transfer per bond is universally described by D=Δχ/ΔR, relating electronegativity and atomic size differences.

Conclusions:

• The choice of substrate significantly influences the preferred phosphorene polymorph and synthesis conditions.
• Synthesis conditions, particularly the source of phosphorus atoms (e.g., P4 molecules), can alter substrate suitability, with Pt(111) favoring blue phosphorene when using P4.