Photoluminescence Features of Nickel-Nitrogen Complexes in Ib HPHT Diamond Matrix

The multiple color centers based on nickel-nitrogen complexes in synthetic Ib HPHT diamond matrices were optically characterized with an accent on a comparative analysis of temperature dependencies of photoluminescence spectra of two different Ni-N complexes with the phononless electronic transitions at 1.56 eV and 1.66 eV. The comparison shows that the intensities, widths, and energies of the bands of electronic and vibronic optical transitions, as well as temperature dependences of these parameters, measured in temperature range of 77-300 K, are essentially differ due to distinction in electron-vibrational interaction in the complexes.