PAC studies on the formation and stability of acceptor-defect complexes in semiconductors

Abstract

The presence of defects in semiconductors is, on one side, necessary to tune the desired electrical properties, but, on the other side, can influence these properties in an unwanted and often unpredictable way. Different simultaneously present defect species often interact mutually resulting in the formation of molecule-like defect complexes. The perturbed γγ angular correlation (PAC) technique is particularly sensitive to such a complex formation provided that a suitable radioactive probe atom is involved in the defect complex. PAC has contributed to the understanding of the nature, structure and stability of complexes formed between radioactive dopant atoms and different defects in Si, Ge, III–V and II–VI semiconductors. A brief introduction to this technique will be given. After an overview on the work done to study native lattice defects and the interaction between substitutional acceptor and donor atoms, the formation of complexes between acceptor atoms and different interstitial impurity atoms will be discussed in more detail.