Hole-mediated stabilization of cubic GaN

Area of Science:

• Materials Science
• Solid-State Physics
• Computational Chemistry

Background:

• Gallium Nitride (GaN) commonly exists in the hexagonal wurtzite (WZ) phase.
• The cubic zinc-blende (ZB) phase of GaN is desirable for certain electronic properties but is less stable.
• Stabilizing the ZB phase is crucial for advanced semiconductor applications.

Purpose of the Study:

• To propose and theoretically validate a novel method for stabilizing the cubic zinc-blende (ZB) phase of materials with a wurtzite (WZ) ground state.
• To investigate the role of 3d acceptor impurities in stabilizing the ZB phase of Gallium Nitride (GaN).

Main Methods:

• First-principles total energy calculations were employed.
• The study focused on the electronic structure and phase stability of GaN with impurity incorporation.
• Analysis of p-d repulsion between impurity levels and the valence band maximum was performed.

Main Results:

• Incorporating 3d acceptor impurities (Zn, Mn, Cu) into GaN was shown to stabilize the cubic zinc-blende (ZB) phase.
• A larger p-d repulsion in the ZB phase raises the valence band maximum, making ZB stabilization energetically favorable.
• Calculations confirmed that impurity-induced hole creation is less costly in the ZB structure.

Conclusions:

• The proposed impurity incorporation strategy effectively stabilizes the cubic zinc-blende (ZB) phase of GaN.
• This work provides a theoretical foundation for designing and synthesizing ZB-phase GaN and similar materials.
• The findings open new avenues for tailoring semiconductor properties through controlled impurity doping.