Photoluminescence associated with the 1.673, 1.944 and 2.498 eV centres in diamond

Abstract

Measurements are reported of photoluminescence from three defect centres in diamond which have characteristic absorption and emission lines at 1.673 eV, 1.944 eV and 2.498 eV respectively. When excited with plane polarized light the emission from the 1.673 eV centre was found to be unpolarized in agreement with a centre possessing tetrahedral symmetry. Analysis of the polarization of emission of the other centres suggests that the symmetry of the 1.944 eV centre is either monoclinic I or trigonal, and that of the 2.498 eV centre is monoclinic I. A comparison of the absorption and excitation spectra indicates that the lines at 2.887 eV and 2.954 eV and a broad absorption extending from 2.8 eV to higher energies are all associated with the 1.673 eV defect.