Effects of Hubbard U correction on the structural and electronic properties of rutile, anatase and brookite TiO2. (2022)

• Record Type: Journal Article
• Authors: Johari, N.A.; Hamzah, N.; Faizal, A.F.A.; Samat, M.H.; Hassan, O.H.; Ali, A.M.M.; Yahya, M.Z.A.; Taib, M.F.M.
• Is Part Of: Materials today. Volume 66:Part 10(2022)
• Page Start: 4061
• Page End: 4067
• Publication Date: 2022
• Subjects: First-principles calculations -- TiO2 -- Hubbard U -- Electronic properties; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2022.06.192
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: In this work, the first-principles calculations using density functional theory (DFT) was applied to calculate the structural and electronic properties of anatase, rutile and brookite TiO2 phases. The effects of Hubbard U correction on the structural and electronic properties of rutile, anatase TiO2 were explored using the local density approximation (LDA) and generalized gradient approximation (GGA) for Perdew-Burke-Ernzerhof (PBE) and Perdew-Burke-Ernzerhof for solids (PBEsol) method by applying Hubbard corrections Ud in Ti 3 d states and Up in O 2 p states. There are changes in the structural parameters caused by the Hubbard U correction in Ti d states and O p states. The best agreement of U values to improve the electronic band gap of rutile was found at Ud = 3.0 eV and Up = 7.0 eV from LDA, Ud = 2.0 eV, Up = 6.0 eV from GGA-PBEsol for anatase and Ud = 3.0 eV and Up = 4.0 eV for brookite using GGA-PBEsol. The combination of both Ud and Up correction terms managed to widen the band gap of rutile, anatase and brookite TiO2 which is close to the experimental value.