showing 9 related works from this author
Investigation of photoluminescence and amplified spontaneous emission properties of cyanoacetic acid derivative (KTB) in PVK amorphous thin films
2018
This work was supported by European Regional Development Fund within the Project No. 1.1.1.1/16/A/046 and A.Riekstins SIA “Mikrotīkls” donation, administered by University of Latvia Foundation.
Glass-Forming Nonsymmetric DWKdyes with 5,5,5-Triphenylpentyl and Piparazine Moieties for Lightamplification Studies
2018
This work has been supported by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 “To increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure” of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/1/16/035). Financial support provided by A. Riekstins SIA “Mikrotīkls” donation, administered by the University of Latvia is greatly appreciated. There are no conflicts of interest to declare.
Glass-forming derivatives of 2-cyano-2-(4H-pyran-4-ylidene) acetate for light-amplification systems
2019
Abstract A series of 2-cyano-2-(4H-pyran-4-ylidene) acetate derivatives with triphenyl and 9H-carbazole moieties were synthesized and investigated, mostly for potential applications in organic solid state lasers. Synthesized compounds show remarkable amorphous film formation ability, tunable thermal properties (thermal stability varies from 190 °C to 387 °C and glass transition temperature from 94 °C up to 141 °C) with light absorption from 400 nm to 600 nm and photoluminescence from 600 nm up to 800 nm. Dyes with incorporated mono-styryl- electron donating fragment (KTB, KTBC and KTB3K) showed higher photoluminescence quantum yield (PLQY) (from 16% up to 23%), significantly lower amplified…
Optical and amplified spontaneous emission of neat films containing 2-cyanoacetic derivatives
2018
During the last two decades, small organic molecules have been widely studied for potential applications in organic solid-state lasers due to low-cost production, simple processing possibility and physical property tuning ability through chemical structure synthetic modifications. One of the most investigated and applied compound in dye lasers is 4- (dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM). It has shown remarkable properties as a dye in solid-state lasers. One of the drawbacks of this compound is high intermolecular interactions which reduce emission efficiency. Therefore it can be applied only in doped systems in low concentration (around 2 wt%). Recently we hav…
Several Derivatives of 6-(Tert-Butyl)-4H-Pyran-4-Ylidene Malononitrile with Different Amorphous Phase Promoting Substituents for Light-Amplification …
2019
A series of glassy 6-(tert-butyl)-4H-pyran-4-ylidene malononitrile (DCM) derivatives with covalently attached amorphous state promoting bulky 1,1,1-triphenylmethyl (trityl) moieties through several chemical design approaches have been synthesized and investigated for suitability in organic solid state laser applications. Results showed that the bonding type of such functional groups had a considerable influence on glass structure forming dye thermal properties and a slight influence on their optical properties. Thermal stability up to 346 °C was achieved with glass transitions in the range from 39 to 138 °C. Incorporation of bulky triphenyl substituents via ester groups showed remarkable am…
Glassy 2-(1-benzyl-2-styryl-6-methylpyridin-4(1H)-ylidene) fragment containing 1H-indene-1,3(2H)-dione and pyrimidine-2,4,6(1H,3H,5H)-trione derivati…
2020
A series of 2-(1-benzyl-2-(styryl)-6-methylpyridin-4(1H)-ylidene) fragment containing glassy organic compounds have been synthesized from relevant luminescent 4H-pyran-4-ylidene derivatives and investigated as potential solution processable emitters. Glass transition temperatures of synthesized 1H-pyridine compounds are above 100°C with thermal stabilities higher than 260°C. In the solutions of dichloromethane their absorption bands are in the range from 350 nm to 500 nm with photoluminescence from 500 nm to 650 nm. In a contrary to the 4H-pyran-4-ylidene derivatives, the incorporation of various electron acceptor fragments within the 1H-pyridine fragment containing molecules only slightly …
HAPPY Dyes as Light Amplification Media in Thin Films
2021
A series of 1Hamorphous tri-phenyl pyridine (HAPPY) dyes have been synthesized from luminescent triphenyl-group-containing 2-methyl-6-styryl-substituted-4H-pyran-4-ylidene derivatives in reactions with benzylamine and investigated for suitability as solution-processable light-emitting medium components in thin films for amplified spontaneous emission (ASE). Conversion of a 4H-pyrane ring into a 1H-pyridine fragment enables aggregation-induced emission enhancement (AIEE) behavior in the target products and slightly increases thermal stability, glass transition temperatures, and ASE efficiency with PLQY up to 15% and ASE thresholds as low as 46 μJ/cm2 in neat spin-cast films, although thermal…
Glass-forming non-symmetric bis-styryl-DWK-type dyes for infra-red radiation amplification systems
2019
Abstract A series of D-π-A type organic dyes with bulky triphenylmethyl moiety containing 2,6-bis-(4-substituted)styryl-4H-pyran-4-ylidene donor (D) fragments and different electron acceptors (A) were synthesized and investigated, mostly for potential applications in organic solid-state lasers as infra-red (IR) radiation amplification medium. Dye glass transition temperature is above 99 °C with thermal stability in the region from 173 °C to 326 °C which was slightly influenced by the electron acceptor fragment attached to the 4H-pyrane ring in 4-position. Introducing substituents in 4-position within one of the styryl-fragments with stronger electron withdrawing properties decreased ASE exc…
Solution processable piperazine and triphenyl moiety containing non-symmetric bis-styryl-DWK type molecular glasses with light-emitting and amplified…
2018
A series of 2,6-bis-styryl-4H-pyran-4-ylidene fragment containing glassy organic compounds with chemically stable bonding of amorphous phase promoting bulky triphenyl moieties through piperazine structural fragment (DWK-T dyes) in a form of 2-(5,5,5-triphenylpentyl)piperazin-1-yl)styryl)-substituent have been synthesized and investigated as the potential gain medium component for organic solid state laser applications. Physical properties of the dyes vary and are mostly depending from the other styryl-substituent attached to the 4H-pyran-4-ylidene backbone fragment in 6-position. Thermal stability of synthesized dyes is above 312°C with the glass transitions from 97°C to 109°C. Obtained nea…