Trapping and self-trapping in ytterbium-doped oxides with charge transfer luminescence

Temperature dependence of the charge transfer luminescence (CTL) of Yb-doped yttrium aluminum garnet Y3Al5O12-Yb (YAG–Yb) and Yb-doped lutetium aluminum perovskite LuAlO3-Yb (LuAP–Yb) crystals under X-ray excitation and their thermostimulated luminescence are investigated in the temperature range 30–350 K and compared to those of undoped crystals. Simulation using a set of kinetic equations describing the processes of creation of excitons, electron–hole pairs, their trapping and self-trapping, radiative relaxation and quenching is presented for the systems under investigation to analyze qualitatively two different types of experimentally observed temperature dependences: CTL yield decline with the temperature decrease below 110 K as in case of YAG–Yb and constant yield in the same temperature range as in case of LuAP–Yb.