First‐principle investigation of defect‐associated LVM and structural parameter dependency in response to the ground state on‐site Hubbard correction of w‐ZnO

Abstract

AbstractWe report a combined experimental (at 81 K, room temperature) and theoretical Raman study of plasma synthesized ZnO nanoparticles. The linear response method calculates the on‐site Coulomb interaction (Hubbard correction) energies Ud = 12.65 eV and Up = 7.65 eV. The structural changes and hybridization mechanism of the d‐p orbital of Zn and O have shown a significant role in bandgap discrepancies. Density of state (DOS) calculations under the influence of Hubbard correction explains the d‐band energy shift mechanism. Over underestimation of bandgap energies phenomena turns out to be highly sensitive to the choice of pseudopotential, and a series of calculations have been reported to converse to greater accuracy. The theoretical calculation was made possible using generalized gradient approximation (GGA)‐based basis set Perdew, Burke, and Ernzerh (PBE); B3LYP; and local density approximation (LDA). Estimates improve accuracy by including the Hubbard correction energy to the ground state energy calculation using the LDA. We have provided approximations methods suitable for the defect complex study based on our systematic analysis among PBE, B3LYP, and LDA. For the correlated system, the choice of pseudopotential is primarily essential; therefore, the present article also discusses the application of Hubbard correction energy only to a specific orbital and consequences. Experimentally observed fundamental and multiphonon decay processes are explained. The defect trapped hydrogen and defect complex configuration state , m = 1, …, 4, local vibrational mode is observed. Systematic molecular design and simulation support the experimentally reported results. The VZn, in association with a single 1s electron of hydrogen, compromises state followed by silent, and second‐order features are presented.