Defect energetics in ZnO: A hybrid Hartree-Fock density functional study

Abstract

First-principles calculations based on hybrid Hartree-Fock density functionals provide a clear picture of the defect energetics and electronic structure in ZnO. Among the donorlike defects, the oxygen vacancy and hydrogen impurity, which are deep and shallow donors, respectively, are likely to form with a substantial concentration in n-type ZnO. The zinc interstitial and zinc antisite, which are both shallow donors, are energetically much less favorable. A strong preference for the oxygen vacancy and hydrogen impurity over the acceptorlike zinc vacancy is found under oxygen-poor conditions, suggesting that the oxygen vacancy contributes to nonstoichiometry and that hydrogen acts as a donor, both of which are without significant compensation by the zinc vacancy. The present results show consistency with the relevant experimental observations.

Correlated d ferromagnetism and photoluminescence in undoped ZnO nanowires

“…26 Our experiments were carried out in oxygen poor conditions where V o always contributes to the nonstoichiometry. 27 The tunable RTFM in NW samples confirms that oxygen vacancies can be purposely used to establish and regulate the ferromagnetic ordering.…”

Atomic-Level Structural and Electronic Properties of Hybrid Inorganic–Organic ZnO:Hydroquinone Superlattices Fabricated by ALD/MLD

“…46 Concerning previous computational studies on ZnO, PBE0 band gaps of 3.32 and 3.2 eV have been predicted using full-potential linearized augmented-planewave (FLAPW) and projector-augmented-wave (PAW) basis sets, respectively. [47][48][49][50] The band structure of bulk ZnO calculated at the PBE0/TZVP level of theory is shown in Figure 5a and a comparison to the band structures calculated with the SVP and TZVPP level basis sets is shown in Supporting information. Figure 5 also shows the band-projected electron densities for the highest valence band (VB) and the lowest conduction band (CB).…”

Electrical degradation of double-Schottky barrier in ZnO varistors

“…4,6,57,[59][60][61] However, recent atomic-scale investigations focused on point defects in ZnO materials that use first-principles calculations methods have brought to attention refreshed and distinct insight into the properties of defects. Even though various researches carried out by different groups could show certain disparities in predicting the characteristics of native defects inside periodic-structure ZnO system, [62][63][64][65][66][67][68][69][70][71][72][73][74] owing to employing different exchange-correlation approximations, numbers of k-point sampling for Brillouin-zone integration, supercell sizes, corrections for spurious defect interactions, and so forth, meaningful and significant conclusions can still be extracted for native donor defect: (i) V O is the lowest-energy donor defect which means it can be generated in large concentration, whereas it is surprisingly a deep donor, i.e. its (2+/0) transitional level lies ∼1 eV below the conduction band minimum (CBM) and V O at 1+ charge state is unstable; (ii) the formation energy of shallow-donor Zn i is higher compared to V O , and its thermal-dynamic (1+/0) and (2+/1+) transitional levels are predicted as 0.05 and 0.16 eV below the CBM by R. Vidya, 64 and as ∼ 0.05 and ∼ 0.1 eV by F. Oba.…”