Combined solid state phase diagram studies and physical property measurements of the various n-type transparent conducting oxide phases in the CdO-In2O3-SnO2 system were carried out. The 1175C (air) sub-solidus phase diagram was established, including solid-solution limits for binary and ternary compositions. From these limits and electrical property measurements vs. doping and degree of reduction, the prevailing defect mechanisms could be deduced. In addition to intrinsic (native) defects (e.g. O vacancies) and extrinsic donor-doping of the end member compounds (e.g. SnIn. in In2O3), ternary solid solutions exhibited both isovalent doping (e.g. [Cd’In] = [SnIn.] in bixbyite, spinel) and donor-to-acceptor imbalance (e.g. [SnIn.]>[Cd’In] in bixbyite, spinel). Aliovalent doping could also lead to the formation of point defect associates, as in Sn-doped In2O3, as confirmed by combined Rietveld analyses of X-ray and neutron diffraction data. Cation exchange between sub-lattices in the spinel phase played an important role in determining phase stability and band structure. The physical properties of the transparent conducting oxide phases in the CdO-In2O3-SnO2 system were presented for both bulk ceramics and thin films.

Defect Chemistry and Physical Properties of Transparent Conducting Oxides in the CdO-In2O3-SnO2 System. T.O.Mason, G.B.Gonzalez, D.R.Kammler, N.Mansourian-Hadavi, B.J.Ingram: Thin Solid Films, 2002, 411[1], 106-14