InP and AlInP(001)(2 × 4) Surface Oxidation from Density Functional Theory

Area of Science:

• Materials Science
• Surface Science
• Computational Chemistry

Background:

• Indium Phosphide (InP) and Aluminum Indium Phosphide (AlInP) are crucial semiconductors.
• Understanding their initial oxidation stages is vital for device stability and performance.
• Surface atomic structure and electronic properties dictate material behavior.

Purpose of the Study:

• Investigate the atomic structure and electronic properties of InP and AlInP(001) surfaces during initial oxidation.
• Focus on mixed-dimer (2 × 4) surfaces under cation-rich conditions.
• Identify favored adsorption sites for oxygen and their impact on electronic states.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis of atomic structure and electronic properties.
• Investigation of oxygen adsorption on InP and AlInP surfaces.

Main Results:

• For InP, the top In-P dimer is the preferred adsorption site for oxygen.
• For AlInP, the second-layer Al-Al dimer is the favored adsorption site.
• Energetically favorable adsorption sites create group III-O bond states within the bulk band gap, acting as recombination centers.
• Oxidation leads to a reduction in Indium p-state density near the conduction band edge.

Conclusions:

• The study identifies specific oxidation pathways and their impact on InP and AlInP electronic properties.
• The formation of recombination centers due to oxygen adsorption is confirmed.
• These findings are crucial for predicting and controlling the behavior of these semiconductor surfaces in electronic devices.