Transition metal ions in ZnO: Effects of intrashell coulomb repulsion on electronic properties

Abstract

Electronic structure of the transition metal (TM) dopants in ZnO is calculated by first principles approach. Analysis of the results is focused on the properties determined by the intrashell Coulomb coupling. The role of both direct and exchange interaction channel is analyzed. The coupling is manifested in the strong charge state dependence of the TM gap levels, which leads to the metastability of photoexcited Mn, and determines the accessible equilibrium charge states of TM ions. The varying magnitude of the exchange coupling is reflected in the dependence of the spin splitting energy on the chemical identity across the 3d series, as well as the charge state dependence of spin-up spin-down exchange splitting.

Electronic properties of Bi2Se3 dopped by 3d transition metal (Mn, Fe, Co, or Ni) ions

“…If the ILs lie around the topological gap, the strong peaks appear in DOSs and become more delocalized as the dopant concentration increases. The situation is similar to ordinary semiconductors [77][78][79], in which the TM ILs can form clear peaks only if they are weakly hybridized with the host states of the same symmetry.…”

Oxygen Vacancy-Mediated Interfacial Charge Transfer of Au/ZnO Schottky Heterojunctions for Enhanced UV Photodegradation

“…Meanwhile, the photocatalytic activities associated with inherent defects for ZnO are significantly influenced by its different morphologies, including sphere-like, rod-like, flower-like, rice-like, hexagonal disk-like, and other nanostructures [15][16][17][18][19]. Thus, an efficient PEC process for ZnO can be mediated either by the presence of defect states related to morphology, or intentionally created defects within the bandgap through doping with transition metal ions [20].…”

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“…The strong dependence of the Kohn-Sham levels of Co on the charge state is clearly visible in figure2(b). The levels of Co 2+ with seven d electrons are 1-2 eV higher in energy than those of Co 3+ with six electrons, because the intrashell Coulomb repulsion increases with the increasing d-shell occupation[55,56,63]. In particular, the spin-up states of Co 3+ are below the VBM, while both spin-down levels are in the gap: e…”