Vacuum ultraviolet excitation of¹S₀and³P₀emission of Pr³⁺in Sr_0.7La_0.3Al_11.7Mg_0.3O₁₉and SrB₄O₇

Abstract

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 4f2[1S0] state. In the hexa-aluminate this results in the successive emission of two photons. 1S0→1I6 emission is followed by emission from the 3P0 state. The quantum efficiency of the total 3P0 emission is 25%. In the tetra-borate the 3P0 emission is quenched by multiphonon relaxation to the 1D2 state from which only weak emission is observed. In the hexa-aluminate as in the tetra-borate, host lattice excitation does not result in efficient emission from the 1S0 state. In the hexa-aluminate the excitation energy is transferred from the host lattice preferentially to the lower-energy 3PJ and 1I6 states, resulting in 3P0 emission only.