Defects at low temperature in electron-irradiated diamond

Abstract

Man-made boron-doped diamonds have been irradiated with energetic electrons. The effect of the dose, for irradiations performed around 15°K, and the effect of the temperature (in the range 15-250°K) upon the conductivity measured at 12°K have been studied. Isochronal annealing, performed in the temperature range 15-350°K, has shown the presence of several stages associated with the thermal release of carriers from traps and of a recovery stage around 260°K. The activation energy for the recovery of the defect has been measured (1.3 eV) and the recovery kinetics determined. A level situated at about 20 meV below the conduction band has been associated with the defect. It is proposed that this recovery stage (around 260°K) is due to the recombination of vacancy-interstitial pairs through the mobility of the interstitial.