First principle calculations of electronic, band structural, and optical properties of BixSr1-xTiO3 perovskite. (April 2019)

• Record Type: Journal Article
• Authors: Fang, Yuzhen; Kong, Xiangjin; Wang, Dongting; Liu, Junhai; Cui, Shouxin
• Is Part Of: Journal of physics and chemistry of solids. Volume 127(2019)
• Page Start: 107
• Page End: 114
• Publication Date: 2019-04
• Subjects: BixSr1-xTiO3 -- Electronic structure -- Band gap -- Density of states -- Absorption spectra; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2018.11.023
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Based on the first-principles plane-wave ultrasoft pseudopotential method, we set up models of perovskite-type oxides Bix Sr1-x TiO3 (x = 0, 0.25, 0.5, 0.625, 1), and the geomertry optimization, the electronic and band structure were studied. The calculation results show that the binding energy decreases in Bix Sr1-x TiO3 after Sr 2+ replaced by Bi 3+ . The calculations of the band structure show that Bix Ba1-x TiO3 are direct band gap semiconductors. The partial substitution of Bi 3+ ions can increase the band gap and the absorption spectra ranges shift blue, and the values of band gaps are in the order of Bi0.625 Sr0.375 TiO3 > Bi0.5 Sr0.5 TiO3 > Bi0.25 Sr0.75 TiO3 > SrTiO3 > BiTiO3, and the absorption spectrum becomes wider in the order of Bi0.625 Sr0.375 TiO3 > BiTiO3 > Bi0.5 Sr0.5 TiO3 > Bi0.25 Sr0.75 TiO3 > SrTiO3 . Based on the density of states, the top of the valence band is hybridized by O-2p and Sr-5s and the bottom of the conduction band state is mainly constituted by the Ti-3d states and Bi-6p states. The regulation of photo-catalytic activity of the perovskite SrTiO3 can be realized by Bi ions substituting for Sr ions, and Bi-based perovskite BiTiO3 will be a potential photocatalytic material. Graphical abstract: Image 1 Highlights: The perovskite-type oxides Bix Sr1-x TiO3 were investigated using first-principles density functional theory. The binding energy decreases in Bix Sr1-x TiO3 after Sr 2+ replaced by Bi 3+ . Partial substitution at A-sites change the band gaps of Bix Ba1-x TiO3, and the band gap values are in the order of x = 0.625 > x = 0.5 > x = 0.25 > x = 0 > x = 1. The VBM is hybridized by O-2p and Sr-5s and the CBM is mainly constituted by the Ti-3d state and Bi-6p in Bix Ba1-x TiO3 . Bi-based perovskite BiTiO3 would be a potential photocatalytic material.