Rare earth interstitial-complexes in Ge: Hybrid density functional studies

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:409

Article; Proceedings Paper

Igumbor, E.^1,2  Omotoso, E.¹  Danga, H. T.¹  Tunhuma, S. M.¹  Meyer, W. E.¹ 

[1] Univ Pretoria, Dept Phys, ZA-0002 Pretoria, South Africa

[2] Samuel Adegboyega Univ, Dept Math & Phys Sci, Km 1 Ogwa Ehor Rd, Ogwa, Edo State, Nigeria

关键词: Defects;    Formation energy;    Charge state;    Rare earth;   

DOI  :  10.1016/j.nimb.2017.04.044

来源: Elsevier

【 摘 要 】

We present results of the structural, energetic and electronic properties of rare earth (RE) interstitial complexes in Ge (REGeGei; for RE: Ce, Pr, Eu, Er and Tm). We used the Heyd, Scuseria, and Ernzerhof (HSE06) hybrid functional within the framework of density functional theory for all calculations. The energy of formation and charge state transition levels of REGeGei complexes were obtained. For the neutral charge state, the results of the formation energy of the REGeGei, were between 0.21 and 8.14 eV. Amongst the REGeGei, while the CeGeGe, was energetically the most favourable with a binding energy of 3.90 eV, TmGeGei and ErGeGei were not stable with respect to their binding energies. The CeGeGei induced deep donor level with negative-U ordering, the PrGeGei induced shallow levels close to the valence band maximum and the EuGeGei induced a shallow single donor level. (C) 2017 Elsevier B.V. All rights reserved,

【 授权许可】

Free