Luminescence of nano- and macrosized LaP04:Ce,Tb excited by synchrotron radiation

摘要

Comparing the luminescence properties of nanosized and macroscopic LaP0_4:Ce,Tb powders are performed in wide spectral range using synchrotron radiation. In the present study, LaP0_4:Ce,Tb nanopow-der was produced by means of a microwave-induced synthesis in ionic liquids, whereas the bulk sample represents a commercial lamp phosphor. Emission and excitation of both, Ce~3+ and Tb~3+ luminescence, is observed to be different when comparing bulk and nanosized LaPO_4:Ce,Tb. In particular, it was shown that the fine structure of the Ce~3+ as well as the Tb~3+ related emission is poorly resolved for the nanoma-terial. It is suggested that the nanoparticles surface plays a key role regarding the perturbation of rare-earth ions and changes their luminescence properties. Furthermore, it is demonstrated that allowed f-d transitions on Tb~3+ at high energy are significantly suppressed for nanosized LaPO_4:Ce,Tb. Energy transfer is required to initiate Tb~3+ emission even in the vacuum ultraviolet spectral range.