The isolated substitutional gold impurity in bulk silicon is studied in detail using electronic structure calculations based on density-functional theory. The defect system is found to be a non-spin-polarized negative-U centre, thus providing a simple solution to the long-standing debate over the electron paramagnetic resonance signal for gold in silicon. There is an excellent agreement (within 0.03 eV) between the well-established experimental donor and acceptor levels and the predicted stable charge state transition levels, allowing for the unambiguous assignment of the two experimental levels to the (1+/1-) and (1-/3-) transitions, respectively, in contrast to previously held assumptions about the system.
@article{arxiv.1403.6306,
title = {Negative-U properties for substitutional Au in Si},
author = {Fabiano Corsetti and Arash A. Mostofi},
journal= {arXiv preprint arXiv:1403.6306},
year = {2014}
}