Experimental evidence of tetrahedral interstitial and bond-centered Er in Ge

We report on an emission channeling study of the lattice site location of implanted Er in Ge together with its thermal stability. We found direct experimental evidence of Er atoms located on the tetrahedral (T) interstitial site and on the bond-centered (BC) site, with a maximum total occupancy after annealing at 400 degrees C. Whereas Er is expected to occupy the T site in a diamond crystal structure, the observation of BC Er in Ge is more surprising and believed to be related to the Er-vacancy defect in the split-vacancy complex configuration. (C) 2008 American Institute of Physics.status: publishe