Ab initio study of point defects in PbSe and PbTe: Bulk and nanowire

Journal Article · Fri Nov 14 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4901640· OSTI ID:22402624

Wrasse, E. O. ^[1]; Venezuela, P. ^[2]

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1. Instituto de Física, Universidade Federal de Uberlândia, 38408-100, Uberlândia, MG, Brazil and Departamento de Física, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil)
2. Instituto de Física, Universidade Federal Fluminense, 24210-346, Niteroi, RJ (Brazil)

First principles investigations, within the spin-polarized density functional theory, are performed to study energetic stability and electronic properties of point defects (vacancies and antisites) in PbSe and PbTe: bulk and nanowire (NW). Our results show that the energetic stability of these defects is ruled by relaxation process. These defects have lower formation energies in the nanowire structures as compared to the bulk, being more stable in the surface of the NWs. We also show that in the bulk system only one charge state is stable, otherwise, due to the larger band gaps, more than one charge state may be stable in the NWs. In addition, we have investigated how the presence of intrinsic defects affects the electronic properties of bulk and NW systems. Vacancies give rise to new electronic states near to the edges of the valence and conduction bands while the energetic position of the electronic states from antisites depends on the charge state, being localized inside the band gap or near the edges of the valence or conduction bands. We discuss how these changes in the electronic properties due to intrinsic defects may affect the thermoelectric properties of PbSe and PbTe NWs.

• OSTI ID: 22402624
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 18 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHARGE STATES
DENSITY FUNCTIONAL METHOD
FORMATION HEAT
LEAD SELENIDES
LEAD TELLURIDES
RELAXATION
SPIN ORIENTATION
SURFACES
THERMOELECTRIC PROPERTIES
VACANCIES