Effect of In-Doping on Electronic Structure and Optical Properties of Sr2TiO4
YUN Jiang-Ni1, ZHANG Zhi-Yong1, YAN Jun-Feng1, ZHANG Fu-Chun2
1School of Information Science and Technology, Northwest University, Xi'an 7101272College of Physics and Electronic Information, Yan'an University, Yan'an 716000
Effect of In-Doping on Electronic Structure and Optical Properties of Sr2TiO4
YUN Jiang-Ni1, ZHANG Zhi-Yong1, YAN Jun-Feng1, ZHANG Fu-Chun2
1School of Information Science and Technology, Northwest University, Xi'an 7101272College of Physics and Electronic Information, Yan'an University, Yan'an 716000
摘要The effect of In doping on the electronic structure and optical properties of Sr2TiO4 is investigated by a first-principles calculation of plane wave ultrasoft pseudopotentials based on density functional theory. The calculated results reveal that corner-shared TiO6 octahedra dominate the main electronic properties of Sr2TiO4 and the covalency of the Ti-O(1) bond in the ab plane is stronger than that of the Ti-O(2) bond along the c-axis. After In doping, there is a little lattice expansion in Sr2In0.125Ti0.875O4 and the interaction between the Ti-O bond near the impurity In atom is weakened. The binding energies of Sr2TiO4 and Sr2In0.125Ti0.875O4 estimated from the electronic structure calculations indicate that the crystal structure of Sr2In0.125Ti0.875O4 is still stable after doping, but its stability is lower than that of undoped Sr2TiO4. Moreover, the valence bands (VBs) of the Sr2In0.125Ti0.875O4 system consist of O 2p and In 4d states, and the mixing of O 2p and In 4d states makes the top VBs shift significantly to high energies, resulting in visible light absorption. The adsorption of visible light is of practical importance for the application of Sr2TiO4 as a photocatalyst.
Abstract：The effect of In doping on the electronic structure and optical properties of Sr2TiO4 is investigated by a first-principles calculation of plane wave ultrasoft pseudopotentials based on density functional theory. The calculated results reveal that corner-shared TiO6 octahedra dominate the main electronic properties of Sr2TiO4 and the covalency of the Ti-O(1) bond in the ab plane is stronger than that of the Ti-O(2) bond along the c-axis. After In doping, there is a little lattice expansion in Sr2In0.125Ti0.875O4 and the interaction between the Ti-O bond near the impurity In atom is weakened. The binding energies of Sr2TiO4 and Sr2In0.125Ti0.875O4 estimated from the electronic structure calculations indicate that the crystal structure of Sr2In0.125Ti0.875O4 is still stable after doping, but its stability is lower than that of undoped Sr2TiO4. Moreover, the valence bands (VBs) of the Sr2In0.125Ti0.875O4 system consist of O 2p and In 4d states, and the mixing of O 2p and In 4d states makes the top VBs shift significantly to high energies, resulting in visible light absorption. The adsorption of visible light is of practical importance for the application of Sr2TiO4 as a photocatalyst.
YUN Jiang-Ni;ZHANG Zhi-Yong;YAN Jun-Feng;ZHANG Fu-Chun. Effect of In-Doping on Electronic Structure and Optical Properties of Sr2TiO4[J]. 中国物理快报, 2009, 26(6): 67102-067102.
YUN Jiang-Ni, ZHANG Zhi-Yong, YAN Jun-Feng, ZHANG Fu-Chun. Effect of In-Doping on Electronic Structure and Optical Properties of Sr2TiO4. Chin. Phys. Lett., 2009, 26(6): 67102-067102.
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2009, Vol. 26 
