Spectroscopic study of NE8 defect in synthetic diamond for optical thermometry

We carried out a laser spectroscopic investigation of high-pressure, high-temperature (HTHP) synthetic diamond containing NE8 defects. In the photoluminescence (PL) emission spectra the defects have a zero-phonon line (ZPL) at 794 nm. Under 730 nm excitation the width and position of the ZPL as well as the Debye-Waller factor showed systematic temperature dependences which were modelled in accordance of a modified model of impurity defects in...