Hopping versus bulk conductivity in transparent oxides: 12CaO - 7Al₂O₃

Author

Julia E. Medvedeva, Missouri University of Science and TechnologyFollow
Arthur J. Freeman

Abstract

First-principles calculations of the mayenite-based oxide, [Ca₁₂Al₁₄O₃₂]²⁺(2e-), reveal the mechanism responsible for its high conductivity. A detailed comparison of the electronic and optical properties of this material with those of the recently discovered transparent conducting oxide, H-doped UV-activated Ca₁₂Al₁₄O₃₃, allowed us to conclude that the enhanced conductivity in [Ca₁₂Al₁₄O₃₂]²⁺(2e-) is achieved by elimination of the Coulomb blockade of the charge carriers. This results in a transition from variable range-hopping behavior with a Coulomb gap in H-doped UV-irradiated Ca₁₂Al₁₄O₃₃, to bulk conductivity in [Ca₁₂Al₁₄O₃₂]²⁺(2e-). Further, the high degree of delocalization of the conduction electrons obtained in [Ca₁₂Al₁₄O₃₂]²⁺(2e-) indicates that it cannot be classified as an electride, as originally suggested.

Recommended Citation

J. E. Medvedeva and A. J. Freeman, "Hopping versus bulk conductivity in transparent oxides: 12CaO - 7Al₂O₃," Applied Physics Letters, vol. 85, no. 6, pp. 955 - 957, American Institute of Physics (AIP), Aug 2004.

The definitive version is available at https://doi.org/10.1063/1.1781362

Department(s)

Physics

Keywords and Phrases

Absorption Peaks; Atomic Sphere Approximation; Charge Density; Electron Hopping; Band Structure; Boundary Conditions; Coordination Reactions; Electric Charge; Electric Conductivity; Electron Transport Properties; Electronic Density Of States; Electronic Properties; Light Absorption; Negative Ions; Optical Properties; Optoelectronic Devices; Calcium Compounds

International Standard Serial Number (ISSN)

0003-6951

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2004 American Institute of Physics (AIP), All rights reserved.

Publication Date

01 Aug 2004