Fluorescence properties of bismuth-doped LaPo4

The following investigation concerns the identification of mechanisms responsible for the blue emission obtained with bismuth-doped lanthanum phosphate LaPO 4 (Bi). Observations of absorption, excitation and fluorescence spectra, together with measurements of the decay time from liquid He up to room temperature are presented. The unexpected variation in the fluorescence decay time below 20K makes this sample particularly interesting compared with materials in which the emission and excitation processes could have been attributed to the so called 'bismuth-isolated centre' alone.