EXAFS study of the structural properties of In and In + C implanted Ge

The structural configurations of In implanted Ge have been studied via x-ray absorption spectroscopy with and without the codoping of C. In the case of In singly implanted Ge, while the In atoms occupy an substitutional site in Ge (InGe4) at low In concentration (≤0.2 at. %), they precipitate into a metallic phase (In metal) and form complexes composed of one vacancy and three Ge atoms (InVGe3) at concentration ≥ 0.6 at. %. This behaviour can be suppressed by the addition of C leading to In-C pairing to form InCGe3 complexes. This cluster enables In atoms to recover a four-fold coordinated structure and has the potential to improve the electrical activation of In atoms in Ge.We acknowledge access to NCRIS and AMMRF infrastructure at the Australian National University including the Australian National Fabrication Facility, the Heavy Ion Accelerator Capability and the Center for Advanced Microscopy. We also thank the Australian Research Council and the Australian Synchrotron for support