Native defects in oxide semiconductors: a density functional approach.

Area of Science:

• Materials Science
• Solid-State Physics
• Computational Chemistry

Background:

• Native defects significantly influence the electrical and optical properties of oxide semiconductors.
• Understanding these defects is crucial for tailoring material functionalities.

Purpose of the Study:

• To investigate native defects in ZnO, SrTiO3, and SnO using computational methods.
• To elucidate the role of specific defects in the conductivity and properties of these oxides.

Main Methods:

• Semilocal and hybrid Hartree-Fock density functional theory calculations.
• Analysis of defect formation energies and electronic structures.

Main Results:

• In ZnO, Zn interstitials are shallow donors, while O vacancies create deep states; H impurities are suggested as the source of n-type conductivity.
• Ti antisites in SrTiO3, alongside O vacancies, explain observed optical and ferroelectric properties.
• Sn vacancies in SnO act as shallow acceptors, contributing to p-type conductivity.

Conclusions:

• Native defects play complex roles, with specific defects like H in ZnO and Ti antisites in SrTiO3 being critical.
• Computational studies provide essential insights into defect behavior and material properties.
• Defect engineering remains a key strategy for developing advanced oxide semiconductor devices.