Photoluminescence spectra of intrinsic interstitials in IIa diamond after near threshold energy irradiation

Abstract In this work, the intrinsic optical defects are created by near threshold energy electron irradiation and then the low temperature micro-photoluminescence (PL) spectroscopy is employed to investigate the dependences of laser power and measurement temperature. The optical centers include 1.673 eV, 2.091 eV and 2.253 eV. Compared with the emissions of 2.091 eV and 2.253 eV, the 1.673 eV emission has an obviously higher growth rate in intensity with the increase of laser power, a larger lattice relaxation, the stronger electron-phonon coupling strength, indicating that they are associated with the different defects. These results show that the 2.091 eV and 2.253 eV emissions are attributed to the self-interstitial defects.