Geometric, electronic and optical properties of zinc/tin codoped In sub(2)O sub(3) modulated by the bixbyite/corundum phase transition

• Published in: Journal of physics. D, Applied physics Applied physics, 2016-02, Vol.49 (6), p.65105-65112
• Main Authors: Lu, Ying-Bo, Li, Y H, Ling, Z C, Cong, Wei-Yan, Zhang, Peng, Xin, Y Q, Yang, T L
• Format: Article
• Language: English
• Subjects: Cations; Corundum; Dopants; Electronics; Indium oxides; Phase transformations; Tin; Zinc
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/49/6/065105

As transparent conducting oxides (TCOs), In sub(2)O sub(3) in the high pressure phase attracts extensive research interests. Because physical properties are determined by the geometric structures, we investigate the electronic and optical properties of Zn/Sn codoped In sub(2)O sub(3) materials (IZTO) being modulated by the bixbyite/corundum phase transition via Density Functional Theory calculations. For IZTO in high pressure phase, i.e. corundum phase, Sn/Zn dopant pair tends to form face-sharing ZnO sub(6) and SnO sub(6) octahedrons. The radius differences between Zn super(2+)/Sn super(4+) dopants and In super(3+) host cations make Jahn-Teller effect occur and IZTO transform from bixbyite to corundum phase under a slight higher pressure than that of pure In sub(2)O sub(3). Although Zn/Sn cosubstitution of In ions may increase the free carrier effective mass m super(*) near the band edge, when IZTO crystal transforms to corundum phase, the more dense packing structure results in stronger cation s-orbital overlaps than in bixbyite phase, which makes m super(*) recover to a smaller value. In addition, corundum IZTO has a larger indirect band gap and a high dopant solubility. So these investigations may open a new way to search for TCOs materials with low indium content.