The electronic structures and optical properties of β-Ga_2O_3 and Si-and Sn-doped β-Ga_2O_3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-...The electronic structures and optical properties of β-Ga_2O_3 and Si-and Sn-doped β-Ga_2O_3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-Ga_2O_3 are in good agreement with experimental results. Si-and Sn-doped β-Ga_2O_3 tend to form under O-poor conditions, and the formation energy of Si-doped β-Ga_2O_3 is larger than that of Sn-doped β-Ga_2O_3 because of the large bond length variation between Ga–O and Si–O. Si-and Sn-doped β-Ga_2O_3 have wider optical gaps than β-Ga_2O_3, due to the Burstein–Moss effect and the bandgap renormalization effect. Si-doped β-Ga_2O_3 shows better electron conductivity and a higher optical absorption edge than Sn-doped β-Ga_2O_3, so Si is more suitable as a dopant of n-type β-Ga_2O_3, which can be applied in deep-UV photoelectric devices.展开更多
The effects of Fe-C/N co-doping on the electronic and optical properties of NaTaO3 are studied with density func- tional theory. Our calculations indicate that mono-doped and co-doped sodium tantalate are both thermod...The effects of Fe-C/N co-doping on the electronic and optical properties of NaTaO3 are studied with density func- tional theory. Our calculations indicate that mono-doped and co-doped sodium tantalate are both thermodynamically stable. The co-doping sodium tantalate can reduce the energy band gap to a greater degree due to the synergistic effects of Fe and C （N） atoms than mono-doping sodium tantalate, and has a larger optical absorption of the whole visible spectrum. The band alignments for the doped NaTaO3 are well positioned for the feasibility of hydrogen production by water splitting. The Fe--C co-doping can enhance the absorption of the visible light and its photocatalytic activity more than Fe-N co-doping due to the different locations of impurity energy levels originating from their p-d hybridization effect.展开更多
基金Project supported by the Science and Technology Program of Guangdong Province,China(Grant No.2015B010112002)the Science and Technology Project of Guangzhou City,China(Grant No.201607010250)
文摘The electronic structures and optical properties of β-Ga_2O_3 and Si-and Sn-doped β-Ga_2O_3 are studied using the GGA + U method based on density functional theory. The calculated bandgap and Ga 3d-state peak of β-Ga_2O_3 are in good agreement with experimental results. Si-and Sn-doped β-Ga_2O_3 tend to form under O-poor conditions, and the formation energy of Si-doped β-Ga_2O_3 is larger than that of Sn-doped β-Ga_2O_3 because of the large bond length variation between Ga–O and Si–O. Si-and Sn-doped β-Ga_2O_3 have wider optical gaps than β-Ga_2O_3, due to the Burstein–Moss effect and the bandgap renormalization effect. Si-doped β-Ga_2O_3 shows better electron conductivity and a higher optical absorption edge than Sn-doped β-Ga_2O_3, so Si is more suitable as a dopant of n-type β-Ga_2O_3, which can be applied in deep-UV photoelectric devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.51572219 and 11204239)the Project of the Natural Science Foundation of Shaanxi Province,China(Grant Nos.2015JM1018,2013JQ1018,and 15JK1714)+1 种基金the Project of Natural Science Foundation of Department of Education of Shaanxi Province,China(Grant No.15JK1759)the Science Foundation of Northwest University of China(Grant No.12NW06)
文摘The effects of Fe-C/N co-doping on the electronic and optical properties of NaTaO3 are studied with density func- tional theory. Our calculations indicate that mono-doped and co-doped sodium tantalate are both thermodynamically stable. The co-doping sodium tantalate can reduce the energy band gap to a greater degree due to the synergistic effects of Fe and C （N） atoms than mono-doping sodium tantalate, and has a larger optical absorption of the whole visible spectrum. The band alignments for the doped NaTaO3 are well positioned for the feasibility of hydrogen production by water splitting. The Fe--C co-doping can enhance the absorption of the visible light and its photocatalytic activity more than Fe-N co-doping due to the different locations of impurity energy levels originating from their p-d hybridization effect.
