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Abstract
Sr(SCN)2:Eu2+(Strontium Thiocyanates doped with Europium 2+) shows strong
luminescence quenching at relatively low temperatures. It has been suggested that
this quenching is due to the thermal promotion of the excited electrons into the
conduction band, followed by nonradiative relaxation back to the ground state.
In this thesis we report on experiments to conflrm the quenching mechanism in
Sr(SCN)2:Eu2+. Because the sample is highly hygroscopic and has to be kept sealed
in a quartz vial under an argon atmosphere, the experimental determination of
the ionization onset is challenging. We are using thermally stimulated lumines-
cence (TSL) as a non-contact technique to probe the onset between the impurity
ground state relative to the host conduction band. We conflrm that the quenching
in Sr(SCN)2:Eu2+is due to photo-ionization.