No trace of divacancies at room temperature in germanium

Alpha-particle irradiated n+p-mesa diodes of Ge were investigated by conventional deep level transient spectroscopy and high-resolution Laplace deep level transient spectroscopy. The electronic and annealing properties of the observed hole traps were studied. It is concluded that none of the observed traps which are stable at room temperature are related to the divacancy. These results are consistent with previous optical studies. They are, however, in disagreement with recent numerical density function calculations which predict a stable divacancy at room temperature with band-gap levels in the lower half of the band gap.