Two-dimensional mono-elemental semiconductor with electronically inactive defects: the case of phosphorus

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Physics

Background:

• Defects in semiconductors, particularly deep gap states, degrade optoelectronic device performance.
• Two-dimensional (2D) metal dichalcogenides (MX2) face limitations due to defect-induced deep gap states.
• A need exists for novel 2D semiconductors free from such detrimental defect states.

Purpose of the Study:

• To investigate the potential of 2D mono-elemental semiconductors as alternatives to MX2.
• To explore the defect properties of 2D phosphorus (P) using first-principles calculations.
• To understand how defects and passivation affect the electronic structure of 2D P.

Main Methods:

• First-principles calculations were employed to study defect properties in 2D phosphorus.
• Analysis of intrinsic point defects and grain boundaries in 2D P.
• Investigation of edge states and the effect of hydrogen passivation on 2D P.
• Computational study of carrier concentration and type tuning via doping in 2D P.

Main Results:

• Most intrinsic point defects and grain boundaries in 2D P are electronically inactive due to homoelemental bonding.
• Unlike MX2, edge states in 2D P can be eliminated by hydrogen termination, preventing deep gap states.
• The carrier type and concentration in 2D P can be effectively tuned through doping with foreign atoms.

Conclusions:

• 2D mono-elemental semiconductors, exemplified by 2D P, are promising candidates for high-performance optoelectronic devices.
• The homoelemental bonding in 2D P inherently suppresses deep gap states, a significant advantage over MX2.
• Hydrogen passivation and doping offer pathways to control the electronic properties of 2D P, highlighting its potential for tailored applications.