Luminescence of Pr-Doped Cs x Rb 1 – x Pb 2 Br 5 Crystals

— Excitation and spontaneous photoluminescence spectra of Cs x Rb 1 – x Pb 2 Br 5 :Pr (0.8 at % Pr) crystals have been studied at different cesium concentrations ( x = 0.1, 0.2, and 0.3) and temperatures. The Stokes luminescence intensity in the praseodymium-doped crystals in the red spectral region has been shown to increase with increasing cesium concentration. We have determined the activation energy for the thermal quenching of visible emission bands of the crystals under excitation with blue light at 450 nm and identified the corresponding electron transitions in emission centers (praseodymium ions) for different luminescence bands.