Site symmetry analysis of the 738 nm defect in diamond

Based on a detailed analysis of polarized Raman and luminescence measurements of a ‘‘mosaic’’ diamond film, symmetry properties of a ubiquitous point defect observed in diamond films are determined. Specifically, the defect, which gives rise to emission at 738 nm, is determined unequivocally to be a 〈110〉-oriented defect with the transition dipole moment of the center oriented along the 〈110〉 symmetry axis. These results represent the first analysis of the symmetry properties of this point defect and aid in the development of structural model of the center.