Electronic structure, donor and acceptor transitions, and magnetism of $3d$ impurities in ${\text{In}}_{2}{\text{O}}_{3}$ and ZnO

Electronic structure, donor and acceptor transitions, and magnetism of $3 d$ impurities in ${In}_{2} O_{3}$ and ZnO

Hannes Raebiger, Stephan Lany, and Alex Zunger

Phys. Rev. B 79, 165202 – Published 8 April 2009

Abstract

$3 d$ transition impurities in wide-gap oxides may function as donor/acceptor defects to modify carrier concentrations, and as magnetic elements to induce collective magnetism. Previous first-principles calculations have been crippled by the LDA error, where the occupation of the $3 d$ -induced levels is incorrect due to spurious charge spilling into the misrepresented host conduction band, and have only considered magnetism and carrier doping separately. We employ a band-structure-corrected theory, and present simultaneously the chemical trends for electronic properties, carrier doping, and magnetism along the series of $3 d^{1} - 3 d^{8}$ transition-metal impurities in the representative wide-gap oxide hosts ${In}_{2} O_{3}$ and ZnO. We find that most $3 d$ impurities in ${In}_{2} O_{3}$ are amphoteric, whereas in ZnO, the early $3 d$ ’s (Sc, Ti, and V) are shallow donors, and only the late $3 d$ ’s (Co and Ni) have acceptor transitions. Long-range ferromagnetic interactions emerge due to partial filling of $3 d$ resonances inside the conduction band and, in general, require electron doping from additional sources.