Vacuum ultraviolet excitation of 1S0 and 3P0 emission of Pr3+ in Sr0.7La0.3Al11.7Mg0.3O19 and SrB4O7

The emission and excitation properties of a SrB4O7:1% Pr3+ powder sample and a Sr0.7La0.3Al11.7Mg0.3O19:3.5% Pr3+ single crystal were investigated using x-ray and synchrotron radiation. The 4f5d states of Pr3+ in these host lattices are at a higher energy than the 4f(2)[S-1(0)] state. In the hexa-aluminate this results in the successive emission of two photons. S-1(0) --> I-1(6) emission is followed by emission from the P-3(0) state. The quantum efficiency of the total P-3(0) emission is 25%. In the terra-berate the P-3(0) emission is quenched by multiphonon relaxation to the D-1(2) state from which only weak emission is observed. In the hexa-aluminate as in the tetra-berate, host lattice excitation does not result in efficient emission from the S-1(0) state. In the hexa-aluminate the excitation energy is transferred from the host lattice preferentially to the lower-energy P-3(J) and I-1(6) states, resulting in P-3(0) emission only.