Akademik Veri Yönetim Sistemi
Journal of Physics and Chemistry of Solids, cilt.213, 2026 (SCI-Expanded, Scopus)
Realizing stable p-type ZnO remains challenging because substitutional nitrogen usually forms deep acceptors. Using self-consistent DFTB (D3; COSMO water), we sequentially replace up to nine surface O atoms by N in a wurtzite ZnO nanoparticle and evaluate formation energetics and electronic structure in vacuum and water. The total formation energy increases nearly linearly with N content, but each substitution costs only about 0.40 eV in the gas phase and even less in water, indicating that N incorporation can be thermodynamically accessible under wet-chemical conditions. An analysis of incremental formation energies shows that low and moderate N loadings are strongly preferred over heavily doped states at typical synthesis temperatures. The cage-like framework is retained, while the dipole moment grows and reorients with N loading. Nitrogen introduces N-2p acceptor states at the valence-band edge, narrowing the gap from 2.96 eV (gas, pristine) to 2.49–2.77 eV (N-doped) and from 3.00 eV (water, pristine) to 2.61–2.89 eV (N-doped). Conceptual-DFT descriptors indicate progressive softening with increasing N content, and at the highest dopant levels the N-2p manifold merges with valence states, yielding a finite DOS at the Fermi level that remains robust under finite-temperature smearing. For representative NP, vertical ΔSCF benchmarks provide a quantitative calibration for Koopmans-based reactivity descriptors. Overall, the calculations rationalize the experimentally reported 2.5–3.0 eV gaps for ultrasmall ZnO and identify moderate N substitution as an acceptor-like electronic-structure regime that enables red-shifted ZnO nanostructures for optoelectronic and sensing applications, whereas heavier doping is more appropriate when enhanced conductivity or catalytic activity is targeted.