Phase coexistence and metal-insulator transition in few-layer phosphorene: a computational study

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Phosphorus exists in various allotropes, including layered α-P (black) and β-P (blue).
• Understanding new allotropes is crucial for developing advanced materials with unique electronic properties.

Purpose of the Study:

• To identify and characterize novel stable structural phases of layered phosphorus.
• To investigate the electronic properties and potential applications of these new phosphorus allotropes.

Main Methods:

• Utilized ab initio density functional calculations to explore potential phosphorus structures.
• Analyzed the stability and electronic band structures of predicted allotropes.

Main Results:

• Proposed two new stable layered phosphorus phases: γ-P and δ-P.
• Observed that some allotropes exhibit wide band gaps, while others, like γ-P, show a metal-insulator transition tunable via strain or layer number.
• Demonstrated the ability to seamlessly connect different structural phases without energy cost.

Conclusions:

• The discovery of γ-P and δ-P expands the known allotropes of layered phosphorus.
• These new phases, particularly γ-P, offer tunable electronic properties, enabling metal-insulator transitions.
• The facile integration of different phases is highly advantageous for constructing complex heterostructures with distinct metallic and semiconducting regions within a single layer.