Indium-Cadmium-Oxide Films having Exceptional Electrical Conductivity and Optical Transparency: Clues for Optimizing Transparent Conductors

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 98; no. 13; pp. 7113 - 7116
• Main Authors: Wang, A., Babcock, J. R., Edleman, N. L., Metz, A. W., Lane, M. A., Asahi, R., Dravid, V. P., Kannewurf, C. R., Freeman, A. J., Marks, T. J.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19-06-2001; National Acad Sciences; The National Academy of Sciences
• Subjects: Charge carriers; Conduction bands; Conductivity; Cubic crystals; Doping; Electrical resistivity; Electricity; Electronic structure; Material films; Physical Sciences; Physics; Superconductivity; Vapor deposition; X ray film
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.121188298

Materials with high electrical conductivity and optical transparency are needed for future flat panel display, solar energy, and other opto-electronic technologies. InxCd
1-xO films having a simple cubic microstructure have been grown on amorphous glass substrates by a straightforward chemical vapor deposition process. The x = 0.05 film conductivity of 17,000 S/cm, carrier mobility of 70 cm2/Vs, and visible region optical transparency window considerably exceed the corresponding parameters for commercial indium-tin oxide. Ab initio electronic structure calculations reveal small conduction electron effective masses, a dramatic shift of the CdO band gap with doping, and a conduction band hybridization gap caused by extensive Cd 5s + In 5s mixing.