Igumbor Emmanuel
University of Pretoria, South Africa
Title: Group II substitutional impurities in Ge: A density functional theory hybrid calculations
Biography
Biography: Igumbor Emmanuel
Abstract
Density functional theory (DFT) calculations of XGe (X = Be, Mg, Ca, Sr and Ba) defects in germanium using the Heyd, Scuseria, and Ernzerhof hybrid functional were performed. The band structures and density of states calculations of the pristine Ge and XGe were presented. The formation energy of charges states −2, −1, 0, +1, and +2 and thermodynamic transition levels were calculated for the XGe . Among the XGe, the MgGe has the lowest formation energy. The XGe introduced deep transition levels in the band gap of Ge. Except the BaGe without double donor level, other XGe displayed the properties of both the double donor and acceptor levels. XGe exhibit the properties of negative−U.