Influence of the Hubbard U Correction on the Electronic Properties and Chemical Bands of the Cubic (Pm(Fromula Presented.)m) Phase of SrTiO3 Using GGA/PBE and LDA/CA-PZ Approximations

Abstract

By using DFT simulations employing the GGA/PBE and LDA/CA-PZ approximations, the effects of the Hubbard U correction on the crystal structure, electronic properties, and chemical bands of the cubic phase (Pm (Formula presented.) m) of STO were investigated. Our findings showed that the cubic phase (Pm (Formula presented.) m) STO’s band gaps and lattice parameters/volume are in reasonably good accordance with the experimental data, supporting the accuracy of our model. By applying the DFT + U method, we were able to obtain band gaps that were in reasonably good agreement with the most widely used experimental band gaps of the cubic (Pm (Formula presented.) m) phase of STO, which are 3.20 eV, 3.24 eV, and 3.25 eV. This proves that the Hubbard U correction can overcome the underestimation of the band gaps induced by both GGA/PBE and LDA/CA-PZ approximations. On the other hand, the Sr-O and Ti-O bindings appear predominantly ionic and covalent, respectively, based on the effective valence charges, electron density distribution, and partial density of states analyses. In an attempt to enhance the performance of STO for new applications, these results might also be utilized as theoretical guidance, benefitting from our precise predicted values of the gap energies of the cubic phase (Pm (Formula presented.) m). © 2024 by the authors. --//-- This is an open-access article Derkaoui, I.; Achehboune, M.; Eglitis, R.I.; Popov, A.I.; Boukhoubza, I.; Basyooni-M. Kabatas, M.A.; Rezzouk, A. Influence of the Hubbard U Correction on the Electronic Properties and Chemical Bands of the Cubic (Pm 𝟑̲ m) Phase of SrTiO3 Using GGA/PBE and LDA/CA-PZ Approximations. Molecules 2024, 29, 3081, https://doi.org/10.3390/molecules29133081 published under the CC BY 4.0 licence.