All-perylene-derivative for white light emitting diodes

Abstract

An organic-based bright white light emitting compound, namely Tb(H3PTC)3, able to be used as part of a white diode and as a part of a RGB system that can withstand...

The Special Case of the Spectral Emission of a Tb3+ Mono Metal Complex

“…Tb(H 3 PTC) 3 shows net magnetic moment, has high fluorescence quantum yield, and its fluorescence in the solid state ranges from green to red, depending on the film thickness. [18] In that work, we showed that this characteristic emission comes from two processes, one scattering involving the exciton with a phonon and an electron and the consequent changing of the molecular Hamiltonian due to the photoinduced charge transfer (PCT) of the scattered electron, both in the neutral and the charged molecules involved in the PCT process. [18] However, the slow variation of the emission peak of the spectra with the film thickness, instead of an abrupt change in energy, could not be explained solely by the processes described above.…”

“…The calculations showed a series of discrete energy levels near the Fermi energy, corresponding to Tb f orbital, which would be the expected result but for every example in the literature reported so far for Tb 3 + mono metal complexes, being the only exception Tb-(H 3 PTC) 3 . [18] The calculations for Tb(H 3 PTC) 3 show that the ligands closest to the terbium atom are characterized by the presence of a À COO group and a carboxyl group, À COOH. Two ligands bind to the terbium through the available oxygen atoms, both oxygen atoms from À COO and one of the À COOH, as indicated by the red arrows in Figure 1, while the third ligand uses only oxygen atoms from À COO to make the bond (blue arrows in Figure 1), keeping the carboxyl group farther from the terbium atom.…”

“…[15][16][17] Recently, a new complex of Tb 3 + was synthesized and the fine structure in the visible emission spectrum was not observed. [18] The molecule is Tb(H 3 PTC) 3 [H 4 PTC = perylene-3,4,9,10-tetracarboxylic acid]. Tb(H 3 PTC) 3 shows net magnetic moment, has high fluorescence quantum yield, and its fluorescence in the solid state ranges from green to red, depending on the film thickness.…”

“…[24,25] Specially in the proposed device, outof-plane vibrations of the pad would decouple from out-ofplane vibrations of the ligand plane because of the 90°o rientation difference between them. The molecule can withstand high temperatures in air, [18] which means that high currents could, in principle, be used. The objective is not to fully describe the theoretical behavior of such a device, because many variables (including vibrational coupling) are involved with actual devices, [26] but to inspire further experimental investigation.…”

“…This suggests the reason why the fluorescence of the molecule slowly varies with the thickness in a film. [18] Exciton recombinations involving this energy levels are sensitive to the molecular environment. In our previous work, we showed that several factors affect the fluorescence output of the molecule in its solid form.…”