Donor-vacancy complexes in Ge: Cluster and supercell calculations

Journal Article · Thu Jun 15 00:00:00 EDT 2006 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.73.235213· OSTI ID:20853258

Coutinho, J; Torres, V J. B.; Barroso, M ^[1]; Oeberg, S ^[2]; Jones, R ^[3]; Briddon, P R ^[4]

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1. Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro (Portugal)
2. Department of Mathematics, Lulea ring University of Technology, Lulea ring S-97187 (Sweden)
3. School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)
4. School of Natural Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU (United Kingdom)

We present a comprehensive spin-density functional modeling study of the structural and electronic properties of donor-vacancy complexes (PV, AsV, SbV, and BiV) in Ge crystals. Special attention is paid to spurious results which are related to the choice of the boundary conditions (supercell-cluster approach), the resulting band-gap width, and the choice of the points to sample the Brillouin zone. The underestimated energy gap, resulting from the periodic conditions together with the local-density approximation to the exchange-correlation energy, leads to defect-related gap states that are strongly coupled to crystalline states within the center of the zone. This is shown to produce a strong effect even on relative energies. Our results indicate that in all E centers the donor atom occupies a nearly substitutional site, as opposed to the split-vacancy form adopted by the SnV complex in Si. The E centers can occur in four charge states, from positive to double negative, and produce occupancy levels at E(0/+)=E{sub v}+0.1 eV, E(-/0)=E{sub v}+0.3 eV, and E(=/-)=E{sub c}-0.3 eV.

• OSTI ID: 20853258
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 73, Issue 23; Other Information: DOI: 10.1103/PhysRevB.73.235213; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIMONY
APPROXIMATIONS
ARSENIC
BISMUTH
BOUNDARY CONDITIONS
BRILLOUIN ZONES
CHARGE STATES
COMPLEXES
COMPUTERIZED SIMULATION
CRYSTALS
DENSITY FUNCTIONAL METHOD
E CENTERS
ELECTRON CORRELATION
ENERGY GAP
EV RANGE
GERMANIUM
IMPURITIES
LEAD
PERIODICITY
PHOSPHORUS
SEMICONDUCTOR MATERIALS
SPIN