RESUMO
An approach to the luminance increase of the europium-based OLED is proposed through the formation of the mixed-ligand complex. The introduction of two diverse anionic ligands around one europium ion forming a mixed-ligand complex is confirmed by powder X-ray diffraction, 1H and 19F NMR spectroscopy, MALDI MS spectroscopy, and luminescence spectroscopy. A decrease in the symmetry of the coordination environment leads to a 50% reduction of the lifetime of the excited state. The obtained OLEDs based on mixed ligand europium complexes are significantly superior in luminance to OLEDs based on individual complexes.
RESUMO
The formation of trimetallic terbium-europium-gadolinium complexes was proposed as an approach to increase the sensitivity of the corresponding terbium-europium complexes for temperature measurement due to the suppression of multiphotonic emission. This approach results in over a 2-fold increase of the sensitivity of Eu-Tb carboxylate, which reached 5.3% K-1 in the physiological range.
RESUMO
An increase in the efficiency for a terbium-based OLED was achieved by introducing gold nanoparticles into the PEDOT:PSS hole injection layer and was mainly due to the improvement in carrier injection and the reduction of the excited-state lifetime. The introduction of plasmon-resonant gold nanoparticles resulted in a 50% increase in the Tb(czb)3TDZP luminance, which reached 480 cd m-2 and is the highest result for OLEDs based on aromatic carboxylates.
Assuntos
Ouro , Nanopartículas Metálicas , TérbioRESUMO
The effect of the emission layer deposition method on the characteristics of OLEDs was studied on the example of the europium mixed-ligand complex Eu(tta)3DPPZ (tta: 2-thenoyltrifluoroacetone, DPPZ: dipyrido[3,2-a:2'c,3'c-c]phenazine). The maximum brightnesses of both OLEDs almost coincided, though OLED based on the spin-coated layer operated at lower voltages. The reason for that was the higher density and smoothness of the solution-processed layer.