Journal of Physics Condensed Matter
The effects of carbon and nitrogen isotopes on the `N3' optical transition in diamond
Gordon Davies, Isaac Kiflawi, G. Sittas, Hisao Kanda
Abstract
The N3 centre in diamond consists of three nitrogen atoms and one vacancy. We show that the N3 zero-phonon line, at 2.985 eV in natural diamond, is shifted by in diamond doped with , with no detectable change in the vibronic bandshape. In diamond, the energies of all the phonons seen in the vibronic band appear to be reduced from diamond in the ratio , and the zero-phonon is shifted by . The carbon isotope shift can be understood in terms of contributions from the lattice expansion, of from the different vibrational frequencies in the ground and excited electronic states, and from the Jahn - Teller effect in the excited state.