S. S. Krasnikova

Exciplex electroluminescence and photoluminescence spectra of the new organic materials based on zinc complexes of sulphanylamino-substituted ligands

We have investigated the electroluminescence spectra of the electroluminescent devices based on the new zinc complexes of amino-substituted benzothiazoles and quinolines containing the C-N-M-N chains in their chelate cycles. The spectra exhibit strong exciplex bands in the green to yellow region 540 to 590 nm due to interaction of the excited states of zinc complexes and triaryl molecules of the hole-transporting layer. For some devices, the intrinsic luminescence band of 460 nm in the blue region is also observed along with the exciplex band giving rise to an almost white color of the device emission. The exciplex band can be eliminated if the material of the hole-transporting layer is not a triarylamine derivative. We have also found the exciplex emission in the photoluminescence spectra of the films containing blends of zinc complex and triphenylamine material.

New Organic Electroluminescent Materials Based on Chelate Metal Complexes

We have synthesized some new chelate metal complexes based on 8-mercaptoquinoline and 8-aminoquinoline derivatives with different metals (Zn, Cd, Ga) and studied their spectral and electroluminescent properties. This is the first use of the compounds containing other heteroatoms instead of oxygen atoms in chelate cycles for OLED applications. The new compounds are characterized by blue and green luminescence. OLEDs prepared on the base of the new materials exhibit bright light emission with an efficiency of about 10 cd/A.

A new class of electroluminescent metal complexes based on quinoline ligands containing the sulfanylamino group

The synthesis and properties of a new class of electroluminescent metal complexes based on quinoline ligands containing the sulfanylamino group in position 8 are described. These complexes contain C-N-M-N chains in the chelate cycles instead of the traditionally used C-O-M-N chains.

Electroluminescent Devices Based on Novel Zinc Complexes of Sulphonylamino Substituted Heterocycles

The electroluminescent properties of some new materials based on novel zinc complexes of sulphonylamino substituted quinolines and 2-phenylbenzazoles are reported. The electroluminescent devices based on the new complexes exhibit a bright luminosity of green or nearly white color with good luminosity efficiency up to 25–30 cd/Å.

Exciplex Electroluminescence Spectra of the New Organic Materials Based on Zinc Complexes of Sulphanylamino-Substituted Ligands

The emission spectra of the electroluminescent devices based on novel zinc complexes of sulphonylamino substituted quinolines, 2-phenylbenzazoles, and oxadiazoles are reported. The spectra exhibit wide intensive bands probably of exciplex nature. The exciplex formation can probably be due to the interaction of nitrogen atoms of amino substituents of a zinc complex and amino-containing molecules of a hole-transporting layer.

The Electroluminescence Spectra of Light-Emitting Devices Based on Zinc Complexes of Amino-Substituted Ligands

Exciplex bands in the electroluminescence (EL) spectra of electroluminescent devices based on the new zinc complexes of amino-substituted benzothiazoles and in the photoluminescence (PL) spectra of the blends of a zinc complex and the triphenylamine derivative are studied. For the EL spectra, it is found that the relation between the exciplex bands and the intrinsic bands of the zinc complex emission depends on the thickness of layers in the EL devices and on the applied voltage. For the PL spectra of blends, this relation strongly depends on the concentration of components.

Exciplex emission from light-emitting diodes based on zinc complexes with sulfonilamino-substituted ligands

We have studied emission spectra from electroluminescent devices based on new zinc complexes with amino-substituted benzothiazoles containing C-N-M-N chains in chelate cycles. The spectra exhibit strong exciplex bands in a green-yellow region of 540–590 nm due to the interaction between excited states of zinc complexes and molecules of triarylamines in the hole-transporting layer. In certain devices, an intrinsic luminescence band is observed in the region of 460 nm together with the exciplex band, and this gives rise to an almost white emission color. The exciplex band can be eliminated if the material of the hole-transporting layer is not a triarylamine derivative. Efficient light-emitting diodes of green, yellow, and white emission colors are developed on the basis of new materials.

Experimental and Theoretical Study of Electroluminescence Spectra of the Light-Emitting Devices Based on Zinc Complexes of Amino-Substituted Ligands

The electroluminescence spectra of the light-emitting devices based on two zinc complexes of amino-substituted ligands Zn(DFP-SAMQ)2 and Zn(PSA-BTZ)2 are studied. The intrinsic and exciplex bands are observed in the spectra, the relation between them being strongly dependent on the material of a hole-transporting layer. A quantum-chemical study of the spectral properties of these complexes and the light-emitting devices based on them using the PBE density functional method is made. To model the spectra of a device, the spectra of the adduct containing one molecule of the zinc complex and one molecule of the hole-transporting material are calculated. The accordance between the experimental and theoretical data is observed.

Some Metal Complexes of 9-Hydroxyphenalenone as Novel Electron Transporting Materials for OLEDs

Aluminum, zinc, beryllium and lithium complexes with 9-hydroxyhyphenalenone are synthesized, and their spectral properties for powders and films are measured. These complexes may be appropriate of applying them for OLEDs. An example of electroluminescent device based on the beryllium complex is presented.

Photo- and electroluminescence of new organic semiconductors

The results of investigation of the luminescence under photo- and electroexcitation for four new compounds are presented. The spectral properties and photoluminescence are studied in ethanol, chloroform solutions and in films formed by thermovacuum deposition (TVD). The phosphorescence of compounds is investigated in ethanol at 77K temperature. The phosphorescence times of molecules are given. The electroluminescence is obtained in multilayered structure ITO/PEDOT/NPD/L /Ca/Al. It is shown, that spectral region of the photoluminescence of TVD films and electroluminescence coincide. Relations of electroluminescence efficiency with molecule structure, photoluminescence quantum yield and possibility of thermally activated delayed fluorescence are discussed.