Electronic structure of the substitutional versus interstitial manganese in GaN

Abstract

Density-functional studies of the electron states in the dilute magnetic semiconductor GaN:Mn reveal major differences for the case of the Mn impurity at the substitutional site Mn_Ga versus the interstitial site Mn_I. The splitting of the two-fold and the three-fold degenerate Mn(d)states in the gap are reversed between the two cases, which is understood in terms of the symmetry-controlled hybridization with the neighboring atoms. In contrast to Mn_Ga, which acts as a deep acceptor, Mn_I acts as a donor, suggesting the formation of Coulomb-stabilized complexes such as (Mn_Ga Mn_I Mn_Ga), where the acceptor level of Mn_Ga is passivated by the Mn_I donor. Formation of such passivated clusters might be the reason for the observed low carrier-doping efficiency of Mn in GaN. Even though the Mn states are located well inside the gap,the wave functions are spread far away from the impurity center. This is caused by the hybridization with the nitrogen atoms, which acquire small magnetic moments aligned with the Mn moment. Implications of the differences in the electronic structure for the optical properties are discussed.

References in corpus (6)

• Molecular Beam Epitaxy of Wurtzite (Ga,Mn)N Films on Sapphire(0001) Showing the Ferromagnetic Behaviour at Room Temperature
• A self-interaction corrected pseudopotential scheme for magnetic and strongly-correlated systems
• Giant Magnetic Moments of Nitrogen Stabilized Mn Clusters and Their Relevance to Ferromagnetism in Mn Doped GaN
• Electronic structure and magnetism of Mn doped GaN
• Ferromagnetism in Mn doped GaAs due to substitutional-interstitial complexes
• On-site Coulomb interaction and the magnetism of (GaMn)N and (GaMn)As

Cited by in corpus (5)

• High-energy spectroscopic study of the III-V nitride-based diluted magnetic semiconductor Ga${}_{1-x}$Mn${}_x$N
• Magneto-optical spectroscopy of (Ga,Mn)N epilayers
• Electronic structure and Jahn-Teller effect in GaN:Mn and ZnS:Cr
• Graphitic-BN Based Metal-free Molecular Magnets From A First Principle Study
• Electronic structure of Diluted Magnetic Semiconductors $G{a}_{1-x}M{n}_{x}N$ and $G{a}_{1-x}C{r}_{x}N$