Vail, John M and Schindel, Daniel and Yang, A. and Penner, Orion and Pandey, Ravi and Jiang, Huitian and Blanco, Miguel Álvarez and Costales, Aurora and Qiu, Qing Chun and Xu, Y. Effect of dielectric polarization on the properties of charged point defects in insulating crystals: the nitrogen vacancy in AlN. Journal of Physics: Condensed Matter, 16 (20). pp. 3371-3378. ISSN 0953-8984 (2004)Full text not available from this repository.
Large unit cell calculations of the properties of charged point defects in insulators largely neglect dielectric polarization of the crystal, because the periodically repeated cells are so small. Embedded quantum cluster calculations with shell-model crystals, representing a single defect in a large crystal, are able to represent the polarization more realistically. For such embedded quantum clusters, we evaluate the optical excitation energy for the nitrogen vacancy in charge state (+3): vN3+ in AlN. This is done with and without dielectric polarization of the embedding crystal. A discrepancy of a few per cent is found, when both ground and excited state orbitals are well-localized within the vacancy. We show that the discrepancy rises rapidly as the excited state becomes more diffuse. We conclude that an embedded cluster approach will be required for transitions that involve even somewhat diffuse states. The investigation is based on a new model for AlN that shows promise for quantitative accuracy.
|Uncontrolled Keywords:||PACS: 77.22.Ej Polarization and depolarization; 61.72.J- Point defects and defect clusters; 71.20.Ps Other inorganic compounds; 78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); 77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.|
|Subjects:||Q Science > QC Physics
Q Science > QD Chemistry
|Research Area:||Economics and Institutional Change|
|Depositing User:||Ms T. Iannizzi|
|Date Deposited:||04 Jul 2012 08:57|
|Last Modified:||04 Jul 2012 08:57|
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