The emission mechanisms of two kinds of Tb complexes doped in PVK system

Two kinds of new rare earth complexes Tb(p-MBA)_3phen (sample Ⅰ) and Tb(p-ClBA)_3phen (sample Ⅱ) were synthesized, and photoluminescence (PL) and electroluminescence (EL) characteristics of the terbium complex and PVK blended system were investigated. As to the sample Ⅰ, the emission of PVK was completely restrained in the EL spectra of the blended film; while in the PL spectra, obvious emission of PVK appeared besides the emission of Tb~ 3+ . But as to the sample Ⅱ, only the green emission from Tb~ 3+ can be observed in both PL and EL spectra of the doping system. So there are two processes that occur in sample Ⅰ, one is the incomplete Frster energy transfer process from PVK to the Tb complex, and the other is the carrier charge trapping process. The main mechanism of sample Ⅱ is the energy transfer process.