Spectral Characteristics and Thermal Quenching of Luminescence in Rb 0.993 Pr 0.007 Pb 2 Br 5 and Rb 0.993 Pr 0.007 Pb 2 Cl 2.5 Br 2.5 Crystals

Crystals with the compositions Rb 0.993 Pr 0.007 Pb 2 Br 5 and Rb 0.993 Pr 0.007 Pb 2 Cl 2.5 Br 2.5 have been grown by the Bridgman method, and the absorption, luminescence excitation, and photoluminescence spectra of these materials in the case of the Stokes mechanism of optical excitation in the blue spectral region have been analyzed. The intensity of the visible luminescence bands of the Pr 3+ praseodymium ions has been shown to depend on the nature of the nearest neighbor atoms in their crystalline environment. This effect is tentatively attributed to changes in the probability of radiative transitions in the rare-earth ion. The temperature dependences of emission intensity obtained for the crystals demonstrate that the contributions of nonradiative recombination channels depend on the transition, which also leads to changes in the emission color of the compounds.