Silicon carbide (SiC) was investigated for deep band gap states of europium
by means of deep level transient spectroscopy (DLTS). The knowledge of the properties of
optoelectrically active impurities or defects is essential for a detailed understanding of the
energy-transfer process resulting in the observable excitations [1].
SiC-samples of the polytypes 4H as well as 6H are ion-implanted by different europium-
isotopes in order to obtain a chemical identification of the characterized energy levels. Here
the concentration sensitivity of the DLTS is applied to observe the elemental transmutation
of the incorporated radioactive tracer atoms 146Eu (t1/2=4.51 d) and 147Eu (t1/2=24.6 d).
DLTS on samples implanted with stable Eu-ions (153Eu) was carried out for comparison
and manifestation of the results. From these studies 5 Eu-related deep band gap levels are
established: in 4H-SiC two levels at EV+0.86(2) eV and EC−0.47(2) eV, and in 6H-SiC three
levels at EV+0.88(2) eV, EC−0.29(2) eV and EC−0.67(2) eV.
