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Three new donor-acceptor molecular glasses were designed and synthesized linking 1,8-naphthalimide and triphenylamino groups though the different bridges. The comprehensive characterization of the compounds was carried out using theoretical and experimental approaches. The compounds showed efficient orange-red emission in solid state with photoluminescence intensity maxima in the range of 584-654 nm. The compounds showed extremely high thermal stability with 5 % weight loss temperatures up to 477 °C. They formed molecular glasses with glass-transition temperatures in the range of 161-186 °C. The fabricated organic light-emitting diodes (OLEDs) based on the developed emitters and conventional host showed maximum external quantum efficiency of 2.5 % in the best case. This value was increased up to 4.7 % by the usage of the host exhibiting thermally activated delayed fluorescence (TADF). OLED containing the TADF host displayed orange emission peaking at 589 nm with colour coordinates x of 0.53 and y of 0.45 combined with power efficiency of 6.7 lm·W

Aiming to develop new deep-red/near-infrared emitters, benzanthrone as a new acceptor moiety with a rigid molecular structure was used. For the design of target compounds phenothiazine and phenoxazine moieties with strong electron-donating ability were also used. Such combination allowed new materials demonstrating thermally activated delayed fluorescence (TADF) in the long wavelength region to be obtained. The maximum intensity of fluorescence of the solid samples of the synthesized compounds was observed at 700 nm. Electroluminescence was peaked at similar wavelength when the compounds were used as emitters for the fabrication of non-doped organic light-emitting diodes. Due to the different substitutions of benzanthrone moieties, the values of TADF lifetimes at room temperature were found to be of in the range of 291–1198 μs which are directory related to their different oxygen sensing properties. Due to high sensitivity to the presence of oxygen in the atmosphere one of the obtained compounds was used for radiometric oxygen sensing. The film of molecular dispersion of phenoxazine containing compound in inert polymer ZEONEX® showed the ratio of intensity of TADF taken in vacuum and of prompt fluorescence taken under oxygen purge of 15.2. The oxygen sensitivity of the film estimated by Stern-Volmer constant was found to be of 1.6 × 10−4 ppm−1 demonstrating good reversibility. The time dependent density functional theory (DFT) calculations were used for the interpretation of the experimental results related to the structure and photophysical properties of the compounds.

Four new derivatives of thianthrene and phenothiazine are reported as emitters for oxygen sensing. They exhibit both fluorescence and phosphorescence at room temperature. Effects of the substitution pattern of phenothiazine moiety on the thermal, electrochemical, emissive and oxygen sensing properties of the compounds are discussed. No phosphorescence at room-temperature was detected for deoxygenated solutions of the compounds. Room temperature phosphorescence of the different intensity was detected for the compounds being in crystalline or amorphous phase and for their dispersions in different polymeric matrices. Fast oxygen response (ca. 0.1 s) of room temperature phosphorescence was observed for only 1 wt.% of the dispersions in polymeric host. The highest oxygen sensitivity, was demonstrated for methylphenothiazinyl-disubstituted thianthrene dispersed in poly(methyl methacrylate). Stern-Volmer constant of 21·10−4 ppm−1 was obtained compared to those of 0.97·10−4, 1.22·10−4 and 2.1·10−4 ppm−1 observed for the dispersions of other compounds. Displaying possibility of oxygen detection by different chromaticity responses of emission of the developed compounds, strong yellowish-green emission with CIE1931 coordinate of (0.294, 0.503) was observed for one sample in the absence of oxygen; while, weak deep-blue emission with CIE1931 coordinate of (0.174, 0.141) was observed for the same sample in oxygen atmosphere.

In the field of materials for optoelectronic applications much attention is paid to the derivatives of triphenylamine and carbazole. We report on the electrochemical and spectroelectrochemical properties of two conductive polymers prepared by electropolymerization of two compounds containing either carbazole or triphenylamine moieties. Electrochemical, UV Vis- and EPR-spectroelectrochemical tools were used to study the properties of the polymers. The basic characteristics such as the band gaps, HOMO and LUMO values, absorption and emission maximum wavelengths of the monomers and the polymers are reported and discussed.

We fabricated a yellow organic light-emitting diode (OLED) based on the star-shaped donor compound tri(9-hexylcarbazol-3-yl)amine, which provides formation of the interface exciplexes with the iridium(III) bis[4,6-difluorophenyl]-pyridinato-N,C2']picolinate (FIrpic). The exciplex emission is characterized by a broad band and provides a condition to realize the highly effective white OLED. It consists of a combination of the blue phosphorescent emission from the FIrpic complex and a broad efficient delayed fluorescence induced by thermal activation with additional direct phosphorescence from the triplet exciplex formed at the interface. The fabricated exciplex-type device exhibits a high brightness of 38 000 cd/m(2) and a high external quantum efficiency.