QUANTUM-CHEMICAL SIMULATION OF EMISSIVE MATERIALS BASED ON MESOGENIC EUROPIUM(III) COMPLEXES FOR ELECTROLUMINESCENT DEVICES
Rubrics: 1. CHEMISTRY
Authors:
1.
KNITU
2.
KNITU
Type:
Article
Pages:
from 26
to 31
Status:
Published
Received:
25.12.2025
Accepted:
25.12.2025
Published:
25.12.2025
Language:
Russian
Keywords:
EUROPIUM(III) COMPLEXES, QUANTUM-CHEMICAL SIMULATION, ENERGIES OF THE EXCITED STATES, INTERMOLECULAR ENERGY TRANSFER
Abstract (English):
Practical application of europium(III) complexes with conducting polymers in optical materials may be limited by low efficiency and self-quenching of luminescence, crystallization and aggregation of molecules in the film of light-emitting material. Experimental selection of polymers and ligands for complexes in order to develop efficient electroluminescent devices is complicated by high costs. To solve such problem, one can apply quantum-chemical methods to predict systems with the best set of photophysical and chemical properties. This work is devoted to the development of approaches to quantum-chemical simulation of efficient emitting materials based on mesogenic europium(III) complexes for electroluminescent devices. During the analysis of the quantum-chemical simulation results, it was found that the optical properties and equilibrium geometry of mesogenic europium(III) complexes can be calculated using semiempirical methods and models such as PM6, SMLC and ZINDO/S. A technique based on the density functional theory was selected, allowing the study of equilibrium geometry and optical properties of some polymers widely used in electroluminescent devices. When analyzing the efficiency of intermolecular energy transfer in systems of europium(III) complexes with polymers, the greatest overlap of the emission spectra of polymers and absorption spectra of complexes, as well as the ratio between the triplet excited levels of polymers and ligands in the complexes, was taken into account. According to the calculated energies of excited levels, emission spectra of polymers and absorption spectra of europium(III) complexes, polymers that provide the most efficient intermolecular excitation energy transfer were selected. The results suggest that the system of polyvinylcarbazole and the europium(III) complex with substituted β-diketones and 1,10-phenanthroline has the highest emission efficiency.
Practical application of europium(III) complexes with conducting polymers in optical materials may be limited by low efficiency and self-quenching of luminescence, crystallization and aggregation of molecules in the film of light-emitting material. Experimental selection of polymers and ligands for complexes in order to develop efficient electroluminescent devices is complicated by high costs. To solve such problem, one can apply quantum-chemical methods to predict systems with the best set of photophysical and chemical properties. This work is devoted to the development of approaches to quantum-chemical simulation of efficient emitting materials based on mesogenic europium(III) complexes for electroluminescent devices. During the analysis of the quantum-chemical simulation results, it was found that the optical properties and equilibrium geometry of mesogenic europium(III) complexes can be calculated using semiempirical methods and models such as PM6, SMLC and ZINDO/S. A technique based on the density functional theory was selected, allowing the study of equilibrium geometry and optical properties of some polymers widely used in electroluminescent devices. When analyzing the efficiency of intermolecular energy transfer in systems of europium(III) complexes with polymers, the greatest overlap of the emission spectra of polymers and absorption spectra of complexes, as well as the ratio between the triplet excited levels of polymers and ligands in the complexes, was taken into account. According to the calculated energies of excited levels, emission spectra of polymers and absorption spectra of europium(III) complexes, polymers that provide the most efficient intermolecular excitation energy transfer were selected. The results suggest that the system of polyvinylcarbazole and the europium(III) complex with substituted β-diketones and 1,10-phenanthroline has the highest emission efficiency.
Keywords:
EUROPIUM(III) COMPLEXES, QUANTUM-CHEMICAL SIMULATION, ENERGIES OF THE EXCITED STATES, INTERMOLECULAR ENERGY TRANSFER
EUROPIUM(III) COMPLEXES, QUANTUM-CHEMICAL SIMULATION, ENERGIES OF THE EXCITED STATES, INTERMOLECULAR ENERGY TRANSFER
