Radiation Induced Defects in Germanium Single Crystals of High Purity

Abstract

Germanium crystals of high purity were irradiated with 1.5 MeV electrons at a high dosage, so that the induced defect concentration exceeded that of the impurity atoms, and most of the defects thus formed were free from the impurity atoms. The crystals were annealed by measuring Hall coefficients and conductivity. The observed annealing stage near 400K was determined to be caused by the migration of divacancies. The activation energy for the annealing was obtained to be 0.93 eV. Large annealing stages at 160K–200K and 210K–260K were also observed and they were considered to be caused by the annealing of unknown defects which did not involve impurity atoms either.