STUDY OF GROUP II IMPURITIES AND STABILITY OF DEFECT-COMPLEXES IN GERMANIUM

  • Igumbor, E. Department of Mathematics and Physical Sciences, Samuel Adegboyega University, Km 1 Ogwa-Ehor Rd, Ogwa Edo State Nigeria.
  • Iyare, B. E. Department of Mathematics and Physical Sciences, Samuel Adegboyega University, Km 1 Ogwa-Ehor Rd, Ogwa Edo State Nigeria.
  • Popoola, F. A. Department of Mathematics and Physical Sciences, Samuel Adegboyega University, Km 1 Ogwa-Ehor Rd, Ogwa Edo State Nigeria.
  • Achurefe, M. Department of Mathematics and Physical Sciences, Samuel Adegboyega University, Km 1 Ogwa-Ehor Rd, Ogwa Edo State Nigeria.

Abstract

Point defects study in Ge is gaining interest due to its influence on the electronic and electrical properties of Ge base devices. Here, we present the ab-initio study of the interactions between vacancy-complexes ((AV)Ge: A = Be, Mg, Ca, Sr, Ba) and vacancy-interstitial complexes in Ge ((AV)GeIA) for the hexagonal (H) and tetrahedral (T) configurations. We used the density functional theory with projector augmented wave pseudopotentials under the framework of the generalized gradient approximation to obtain the results of this study. The geometric structures and formation energies of the (AV)Ge and (AV)GeIA for the neutral charge state were obtained. While the formation energies of the (AV)Ge lies between -2.59 to 4.36 eV, the (CaV)Ge and (SrV)Ge formed with the lowest formation energies of -0.38 and 0.66 eV, respectively. For the H configuration of the (AV)GeIA, results showed that under equilibrium conditions, the energy of formation is relatively lower than that of the T configuration. For vacancy-interstitial complexes in Ge, the (CaV)GeICa and (BeV)GeIBe formed with a lower formation energy of -2.59 and -1.49 eV, respectively. The stability of the (AV)GeIA and (AV)Ge were obtained from their binding energies. The calculated binding energies of both the (AV)GeIA and (AV)Ge showed the ability of these complexes to form without dissociation. For the (AV)GeIA, the H configuration forms with a binding energy that is energetically more favourable than the T configuration. The results of this study are essential as they provide a theoretical framework for the experimental characterisation of defect-complexes in Ge.

Published
2022-07-22
How to Cite
E., Igumbor, et al. STUDY OF GROUP II IMPURITIES AND STABILITY OF DEFECT-COMPLEXES IN GERMANIUM. SAU Science-Tech Journal, [S.l.], v. 7, n. 1, p. 90-99, july 2022. ISSN 2659-1529. Available at: <https://journals.sau.edu.ng/index.php/sjbas/article/view/787>. Date accessed: 30 sep. 2022.
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Articles