  TiSe2 is a member of transition metal dichalcogenide family of layered
van-der-Waals materials that exhibits some distinctive electronic and optical
properties. Here, we perform Raman spectroscopy studies on single crystal TiSe2
to investigate photon-induced defects associated with formation of selenium
vacancies. Two additional Eg phonon peaks are observed in the laser-irradiated
regions, consistent with Raman spectra of selenium deficient TiSe2. Temperature
dependent studies of the threshold laser intensity necessary to form selenium
vacancies show that there is a linear dependence. We extract the relevant
activation energy for selenium vacancy nucleation. The impact of these results
on the properties of strongly correlated electron states in TiSe2 are
discussed.
