Investigation of biphenyl enamines for applications as p-type semiconductors

publishedVersio

Design, synthesis and theoretical simulations of novel spiroindane-based enamines as p-type semiconductors

publishedVersio

New solution-processable carbazole derivatives as deep blue emitters for organic light-emitting diodes

Two new compounds based on three carbazole units connected by triple bonds as π-spacers have been developed as deep blue emitters for organic light-emitting diodes (OLEDs). Their optical and electrochemical properties were examined and their charge carrier transport properties were investigated by means of the xerographic time-of-flight (XTOF) technique. The prepared diodes demonstrate the feasibility of the new molecules as effective emitters in the deep blue region yielding devices with low turn-on voltages

Photo-polymerizable aromatic amines as materials for hole transporting layers

Kauno technologijos universitetasVilniaus universiteta

Molecular glasses possessing a phenyl-1,2,3,4-tetrahydroquinoline moiety as hole transporting materials for electrophotography

The new hole transporting materials which comprise molecules consisting of two hydrazone branches linked with flexible thiobiphenyl or thiophenyl sulphide and two hydroxyl groups containing central bridge were synthesized and investigated. These transporting materials possessing phenyl-1,2,3,4-tetrahydroquinoline moieties are low molecular glasses and allow preparing stable to crystallization layers. The ionization potentials of these compounds are ca. 5.3 eV as determined by the electron photoemission method. These low molecular glasses can be used as hole transporting materials with or, in the case of a solid substrate, without binder polymer. The hole drift mobility of the newly synthesized compounds, measured by xerographic time of flight method, exceeds 10−5 cm2/V s at an electric field of 106 V/cmVytauto Didžiojo universitetasŽemės ūkio akademij

1,3-Diphenylethenylcarbazolyl-Based Monomer for Cross-Linked Hole Transporting Layers

A new cross-linkable monomer containing 1,3-diphenylethenylcarbazolyl-based hole-transporting moieties and four reactive epoxy groups, was prepared by a multistep synthesis route from 1,3-bis(2,2-diphenylethenyl)-9H-carbazol-2-ol and its application for the in situ formation of cross-linked hole transporting layers was investigated. A high concentration of flexible aliphatic epoxy chains ensures good solubility and makes this compound an attractive cross-linking agent. The synthesized compounds were characterized by various techniques, including differential scanning calorimetry, xerographic time of flight, and electron photoemission in air methods

1,3-Diphenylethenylcarbazolyl-Based Monomer for Cross-Linked Hole Transporting Layers

A new cross-linkable monomer containing 1,3-diphenylethenylcarbazolyl-based hole-transporting moieties and four reactive epoxy groups, was prepared by a multistep synthesis route from 1,3-bis(2,2-diphenylethenyl)-9H-carbazol-2-ol and its application for the in situ formation of cross-linked hole transporting layers was investigated. A high concentration of flexible aliphatic epoxy chains ensures good solubility and makes this compound an attractive cross-linking agent. The synthesized compounds were characterized by various techniques, including differential scanning calorimetry, xerographic time of flight, and electron photoemission in air methodsKauno technologijos universitetasVilniaus universitetasVytauto Didžiojo universitetasŽemės ūkio akademij

Methacryloyl functionalized hydrazones as hole-transporting materials for electrophotography

Syntheses and thermal, optical as well as photoelectrical properties of carbazolyl-, triphenylamino- and 2-hydroxy-4-diethylaminophenyl-based hydrazones with reactive methacryloyl groups have been reported. All the synthesized materials form glasses with glass transition temperatures ranging from 9 to 50 degrees C. They absorb electromagnetic radiation in the 250-440 nm range. Ionization potentials of the amorphous films of the synthesized materials, established by electron photoemission technique range from 5.20 to 5.71 eV. The lowest ionization potential and the best charge transport properties were observed for 2-(methacryloyl)oxy-4-diethylaminophenyl-1-carbaldehyde N,N-diphenylhydrazone. Time-of-flight hole mobilities in its 50% solid solution in bisphenol Z polycarbonate reach 10(-5) cm(2)/(V.s) at high electric fieldsVytauto Didžiojo universitetasŽemės ūkio akademij

Electro-active monomers and polymers containing 3-arylcarbazol-9-yl fragments

Monomers and polymers containing 3-arylcarbazol-9-yl fragments were synthesized. The materials were examined by various techniques including differential scanning calorimetry, thermogravimetry, electron photoemission spectrometry and xerographic time of flight technique. The electron photoemission spectra of the layers of the derivatives showed ionization potentials of 5.35–5.45 eV. Hole drift mobilities in the layers of the monomers dispersed in polymeric host bisphenol Z polycarbonate (50%) range from 10−6 to 1.6 × 10−5 cm2 V−1 s−1 at high electric fields at room temperature. The synthesized polymers have been tested as hole-transporting materials in bilayer OLEDs with Alq3 as the emitter. The device with polymer containing (1-naphtyl)phenylamino substituted carbazolyl fragments exhibited the best overall performance with turn-on voltage of 3 V, a maximum photometric efficiency of 4.1 cd/A and maximum brightness of ca. 22,900 cd/m2Kauno technologijos universitetasVilniaus universiteta