Abstract:
The creation of a combined radiative state at 2.95–3.1 eV in the phosphor CaSO4 − Dy3+
has been investigated using vacuum ultraviolet and thermoactivation spectroscopy methods. It is
shown that the combined radiative electronic state is formed from the radiative electronic states of
the impurity electronic trapping centers Dy2+ − SO−
4
and the intrinsic electronic radiative states
SO3−
4 − SO−
4
during the excitation of the anion complex SO2−
4
, as a result of charge transfer from
the excited anion complex O2− − Dy3+ to the impurities and the neighboring anion complex
O2− − SO2−
4
. In the CaSO4 − Dy phosphor, the combined radiative electronic state and impurity emission of Dy3+, 2.16 eV and 2.56 eV are excited by photons with energies of 3.95–4.0 eV and
4.5–4.6 eV. Energy transfer from the matrix to the Dy3+ impurities is revealed upon thermal exposure
as a result of the ionization of the electronic capture centers of Dy2+ and SO3−
4
.
