The energy transfer in the rare earth organic phosphors was discussed. Organic ligands with suitable position of triplet may be used to sensitize the luminescence of rare earth ions

or the position of the triplet of the organic ligands may be estimated according to the position of theof the excited state of the luminescent rare earth ions. The intensity of emission may be enhanced and the emission bands may be splitted by the formation of organic complexes

especially of organic complexes with mixed ligands. But the function groups containing hydrogen such as -OH having high vibronic frequence may quench the luminescence of the rare earth ions

so the intensity of emission and the lifetime may be enhanced by use of the deuterated or fluorinated organic compounds or systems containing other heavy atoms. Therefore

organic solvents or water molecules have important effect on the luminescence of the rare earth ions. Rare earth organic phosphors have been used in such fields as: liquid laser materials

solar luminescence concen-tractor

luminescent plastic films

detection of defects

diagnosis of integrated circuit by thermal imaging

analysis of trace amount of rare earth and luminescent probes for biomolecular systems.