LUMINESCENCE OF TM(III) IONS IN AQUEOUS-SOLUTION AND ORGANIC MATRICES

Luminescence has been observed for the first time in the blue (478 nm) and red (650 and 790 nm) from Tm3+ complexes in organic solution and in a poly(methyl methacrylate) matrix at room temperature. The population of the luminescing levels of the Tm3+ has been achieved by energy transfer from the excited organic ligand molecules. The effect of the ligand both to shield the Tm3+ from the environment, and hence reduce the nonradiative decay to the environment, and to provide an efficient energy transfer route is discussed. From the absorption and emission spectra obtained, the complex of Tm3+ with a 2,6-dipicolinic acid (DPA) as a ligand, and with tetra butyl ammonium ion as the counter ion (Tm(DPA)(3)[N(C4H9)(4)](3)) has shown to be the most promising of the materials under investigation in this study for efficient Tm3+ luminescence.