C. Fischer et al., INFLUENCE OF THE DAMAGE RESISTANT IMPURITIES ZN AND MG ON THE UV-EXCITED LUMINESCENCE IN LINBO3, Physica status solidi. a, Applied research, 137(1), 1993, pp. 247-255
In LiNbO3 the intrinsic uv-excited luminescence in the visible is cont
rolled by the stoichiometry of the crystal and doping with Mg or Zn. E
ither the increase of the Li/Nb ratio or incorporation of Mg or Zn lea
d to the same change of the emission bandshape and intensity. The emis
sion increases with increasing impurity concentration and tends to sat
urate above the values of about 5 mol% Mg or 7 mol% Zn. These are 'thr
esholds' corresponding simultaneously to a drastic reduction of the ph
otorefraction. The luminescence lifetimes are temperature dependent an
d again are governed by impurity concentrations. The results are discu
ssed in terms of the site-antisite model regarding Nb(Li) and Nb(Nb) c
enters to be responsible for the intrinsic luminescence and its kineti
cs in LiNbO3, that means a substitution for Nb(Li) by Mg or Zn.