Jacek Ulanski

Jacek Ulanski
Lodz University of Technology · Department of Molecular Physics

About

286
Publications
31,099
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5,965
Citations
Additional affiliations
January 2000 - present
Centre of Molecular and Macromolecular Studies in Łódź
January 1999 - present
Lodz University of Technology
November 1984 - present
Claude Bernard University Lyon 1
Description
  • research collaboration, visiting professor, exchange of students

Publications

Publications (286)
Article
Full-text available
Free-standing and flexible field-effect transistors based on 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene)/polystyrene bilayers are obtained by well-controlled phase separation of both components. The phase separation is induced by solvent vapor annealing of initially amorphous blend films, leading to crystallization of TIPS-pentace...
Article
Full-text available
The resonance Raman effect (RRE) is a phenomenon which results in a strong selective enhancement of Raman signals from the samples. Previous studies showed that the RRE in liquid water directly corresponds to its supramolecular structure. It was also reported that the electric-field-induced orientation of water molecules on the electrode surface re...
Article
Full-text available
Spherical nano-objects composed of poly(acrylic acid-stat-acrylamide)-block-polystyrene (P(AA-stat-Am)-b-PS) were prepared via polymerization induced self-assembly (PISA) and used as templates for the synthesis of hybrid Ag@P(AA-stat-Am)-b-PS. These well-defined hybrids were used as effective surface-enhanced Raman spectroscopy (SERS) supports for...
Article
Full-text available
Among solution-processable techniques, inkjet printing is a potential method for manufacturing low-cost and high-resolution polymer organic light-emitting diodes (PLEDs) for displays/solid-state lighting applications. Herein, we demonstrate use of the inkjet printed cesium carbonate (Cs2CO3) film as an electron injection interlayer. We have elabora...
Article
Solution processable dielectric nanomaterials were prepared by the polymer-templated synthesis of the hybrid nanoparticles containing TiO2. Well defined poly(styrene-co-acrylonitrile)-b-poly(acrylic acid)-poly(divinylbenzene) (PSAN-b-PAA-PDVB) star-shaped copolymers were prepared by activators regenerated by electron transfer atom transfer radical...
Article
Full-text available
In this work we study the influence of dielectric surface and process parameters on the geometry and electrical properties of silver electrodes obtained by electrohydrodynamic inkjet printing. The cross-section and thickness of printed silver tracks are optimized to achieve a high conductivity. Silver overprints with cross-section larger than 4 µm...
Article
A series of new bis(benzo[h]quinolinato) Ir(III) complexes with modified β-ketoiminato ancillary ligands were synthesized, and their electrochemical, photophysical properties were determined with the support of theoretical calculations. Moreover, all the synthesized heteroleptic Ir(III) complexes were examined as dopants of the host–guest type emis...
Article
Full-text available
The bulk heterojunction based created by poly(3-hexyltiophene-2,5-diyl) (P3HT phenyl-C61-butyric acid methyl ester (C60-PCBM) it is well-known system used in organic solar cells. As the performance of such solar cells are very sensitive to the processing conditions of the active layers, we have focused attention to preaggregation process of P3HT in...
Article
The possibility of efficient work function tuning of high‐quality graphene, grown on 6H‐SiC(0001), by covering it with thermally evaporated rhenium heptoxide (Re2O7) is presented. Raman spectroscopy, X‐ray photoelectron spectroscopy, and ultraviolet electron spectroscopy are used for structural, chemical, and electronic characterization of Re2O7/gr...
Article
Full-text available
In this work we analyse an influence of 80% ethoxylated polyethyleneimine (PEIE) interlayer modifying the ITO electrode work function on the detectivity and time response of the red-light sensitive photodetectors based on donor-acceptor copolymer HFQx-T (where HFQx stands for hexafluoroquinoxaline acceptor units, and T for benzodithiophene derivati...
Chapter
Provides first-hand insights into advanced fabrication techniques for solution processable organic electronics materials and devices The field of printable organic electronics has emerged as a technology which plays a major role in materials science research and development. Printable organic electronics soon compete with, and for specific applica...
Article
This study presents the inkjet printing of a novel OLED device with fully solution-processed organic layers that employ TADF material as an emitting layer. The ink was formulated using new TADF material, triazine core carbazole dendrimers with tert-butyl group at the periphery (tBuG2TAZ), dissolved in a mixture of two non-chlorinated solvents. The...
Article
Full-text available
Inkjet printing technique allows manufacturing low cost organic light emitting diodes (OLEDs) in ambient conditions. The above approach enables upscaling of the OLEDs fabrication process which, as a result, would become faster than conventionally used vacuum based processing techniques. In this work, we use the inkjet printing technique to investig...
Chapter
This chapter presents selected problems related to charge carrier transport in organic semiconductors, with a special emphasis on multicomponent materials, such as heavily doped semiconductors, composites, and nanocomposites. Fundamental concepts, terms, and models, commonly used in the description of both inorganic and organic semiconductors, are...
Article
Full-text available
Charge-carrier transport in the channel of bottom gate, top contact organic field effect transistors with anisotropic layers of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pentacene) obtained by zone casting was investigated using scanning Kelvin probe microscopy combined with atomic force microscopy. The TIPS-Pentacene continuous layers con...
Article
Non-fullerene acceptors based organic photovoltaics (OPVs) have attracted considerable attention in the last decade due to their great potential to realize high-power conversion efficiencies. To achieve higher performance OPVs, the fundamental challenges are in enabling efficient charge separation/transport and a low voltage loss at the same time....
Article
A commercially available, soluble in chlorinated hydrocarbons perylene derivative, N,N-bis(1-ethylpropyl)-perylene-3,4:9,10-bis(dicarboximide) (PTCDI-C5(3)), was used to construct n-channel organic field effect transistors (OFETs). The transistors had the top-gate-bottom-contacts (TGBC) architecture, with a spin-coated layer of the active material....
Article
Herein we report the investigation of non-doped exciplex formed in blends of 2,4,6-Tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T), working as the one-electron acceptor molecule, with different electron donors. The emission of these exciplexes spans from blue to orange-red, and shows clear contribution from thermally activated delayed fl...
Article
Full-text available
This study presents the slot-die coating process of two layers of organic materials for the fabrication of organic light emitting diodes (OLEDs). Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which is commonly used in OLEDs and in organic photovoltaic devices as the hole injection layer (HIL), has been deposited via slot-die c...
Article
Two conjugated polymers, with different side chains of alkoxy substituted difluorobenzene and alkyl substituted difluorothiophene based on quinoxaline (Qx) as the electron acceptor unit and the benzodithiophene (BDT) as the electron donor unit, named HFQx-T and HFAQx-T, were used as electron donor polymers to fabricate all-polymer solar cells (all-...
Article
CdTe/CdS core-shell quantum dots were synthesized and implemented into a light emitting device resulting in multi-channel electroluminescence with a light-green emission color. The main electroluminescence band at about 530 nm corresponds to the emission by the CdTe core (type I core/shell structure), while the next emission band at 595 nm is assig...
Article
To provide high exciton utilization in organic light emitting diodes, phthalimide derivatives were designed and synthesized as exciplex-forming materials. Due to high triplet levels (2.92–3.11 eV) and ionization potentials (7.18–7.29 eV), the developed phthalimide derivatives were found to be not only appropriate accepting materials for the formati...
Article
Poly(2-hydroxyethyl methacrylate) brushes were grown from a gold substrate by Atom Transfer Radical Polymerization (ATRP) and the material was applied as the gate dielectric layer in Organic Thin Film Transistor (OTFT) devices. The ATRP method provided 120 nm thick layers with relatively low roughness, as characterized by Atomic Force Microscopy. T...
Article
We describe the synthesis and photodetecting properties of new, low band-gap copolymers: P1 with 5,6-difluoro-2,1,3-benzothiadiazole and P2 with 2,1,3-benzothiadiazole, both containing diketopyrrolopyrrole acceptor units. These compounds have been used for fabrication of single layer, solution processed photodetectors. For this purpose, two blends...
Article
In this paper we report studies of the electronic structure as well as photophysical and emissive properties of family of new heteroleptic iridium(III) complexes of the general formula [Ir(bzq)2(N^O)] with...
Article
Full-text available
Ambipolar organic field-effect transistors based on binary blends of n- and p-type semiconductors frequently suffer from low or unbalanced electron and hole transport. Uncontrolled phase separation and intermixing of donor and acceptor phases in such thin film blends lead to formation of bulk heterojunctions that lack sufficient percolation paths t...
Article
This paper presents general information about ARUZ, a scalable, fully parallel data processing system equipped with low-latency communication channels, designed for simulations of interactions among huge number of relatively simple elements. ARUZ consists of approximately 26 000 FPGAs and it can represent a system composed of several million elemen...
Article
Photogeneration of charge carriers in closely packed phenyl-C61-butyric acid methyl ester (PCBM) was investigated by means of the xerographic discharge technique. It was found, that position of centre of mass of the thermalized electron is positioned at distance which is integral multiplicity of the centre-to-centre distance between the adjacent PC...
Article
Full-text available
An emerging new technology, organic electronics, is approaching the stage of large-scale industrial application. This is due to a remarkable progress in synthesis of a variety of organic semiconductors, allowing one to design and to fabricate, so far on a laboratory scale, different organic electronic devices of satisfactory performance. However, a...
Article
Three new derivatives of carbazole were synthesized, namely two isomers disubstituted with diarylaminophenyl groups in 2,7- and 3,6- positions (C1 and C2) and diarylaminophenyl symmetrically disubstituted with carbazole C3. All three compounds showed similar electrochemical behavior with one reversible redox couple, originating from the oxidation o...
Article
Full-text available
Iridium C,N-cyclometalated complexes of ionic structure are considered to be promising candidates for application in the host/guest solid-state phosphorescent single-layer devices because the employment of such dopants offers the possibility to reduce their concentration in organic matrices as well as allows to obtain organic light emitting devices...
Article
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We report a strategy for preparing barium titanate precursor, being the composite of titanate nanosheets (TN) with barium ions (Ba-TN), which subjected to step sintering allows obtaining TiO 2 rich barium titanate ceramics of stoichiometry BaTi 4 O 9 or Ba 2 Ti 9 O 20 . These compounds are important in modern electronics due to their required diele...
Article
Ambipolar organic field-effect transistors based on heterojunction active films still suffer from their unbalanced transport of electrons and holes. This problem is related to an uncontrolled phase separation between the donor and acceptor organic semiconductors in the thin film. In this work, we have developed a concept to improve the phase separa...
Article
Since the interfacial order of conjugated polymers plays an essential role for the performance of field-effect transistors, comprehensive understanding on the charge carrier transport in ultrathin semiconducting films below thicknesses of 10 nm is required for the development of transparent and flexible organic electronics. In this study, ultrathin...
Article
In this work we studied the blends of poly(3-hexylthiophene) (P3HT) with 25–75 wt% of either N,N′-dioctyl-3,4,9,10-perylenedicarboximide (PDIC8) or N,N′-dioctyl-1,7-dicyano-3,4,9,10-perylenedicarboximide (PDIC8CN2). In our approach we used differential scanning calorimetry, X-ray diffraction and atomic force and scanning electron microscopies to sh...
Article
Field-effect transistors based on poly(3-hexylthiophene) (P3HT) bulk films exhibit maximum charge carrier mobilities up to 0.1 cm2/Vs. However, reducing the thickness of the polymer film beyond 10 nm results in significant deterioration of the charge transporting properties. In our work, we demonstrate a strategy towards ultrathin (i.e. thinner tha...
Article
One of the most challenging problems limiting the development of the technology of organic electronics is a lack of simple, solution based, techniques for producing organic thin film transistors (OTFTs) with ambipolar characteristics. In this work, a simple method of manufacturing ambipolar OTFTs, based on a zone-casting technique, is presented. Th...
Article
Full-text available
Three new bipolar star-shaped derivatives of 2,4,6-triphenyl-1,3,5-triazine containing carbazolyl groups were designed, synthesized and characterized. All the materials possess high thermal stability and high glass transition temperatures ranging 97-226 degrees C. Photophysical study of the dilute solutions and neat films of the synthesized compoun...
Article
Full-text available
Systematic studies of redox, spectroscopic and electroluminescent properties of donor-acceptor- donor (DAD) electroactive compounds consisting of diketopyrrolopyrrole central accepting unit symmetrically disubstituted with mono-, bi- or terthiophene (T1, T2 and T3 series) are presented. The potential of the diketopyrrolopyrrole unit reduction is in...
Article
In this work we report a reproducible and efficient method of surface modification of titania nanoparticles (rutile) via reversible-deactivation radical polymerization. Herein, we graft poly(di (ethylene glycol) methyl ether methacrylate) from the surface of TiO 2 in an amount of 21 wt% within the reaction time of 3 h 15 min. The amount of grafted...
Article
Full-text available
Copolymers of 2-(2-methoxyethoxy)ethyl methacrylate (poly(MEO2MA)) are regarded as bioinert replacements of poly(N-isopropylacrylamide) in some biomedical applications. Networks of poly(MEO2MA) of various architecture form thermo-responsive hydrogels. Here, we present dielectric and mechanical spectroscopy studies on segmental motions and network r...
Article
Full-text available
Water interacting with a polymer reveals a number of properties very different to bulk water. These interactions lead to the redistribution of hydrogen bonds in water. It results in modification of thermodynamic properties of water and the molecular dynamics of water. That kind of water is particularly well observable at temperatures below the free...
Article
We report on fabrication and characterization of an organic light emitting diode by incorporating a pure DNA as electron blocking layer. As emission layer a thin film of phosphorescent Ir(ppy)(3) luminophore, embedded in the poly(N-vinylcarbazole) (PVK)/2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PBD) is used. The BioLED shows a good...
Article
Full-text available
Three new naphthalene bisimides with alkoxyphenyl N-substituents (abbreviated as NBI-4-n-ORPhs, where R = butyl, hexyl or octyl group) were synthesized as well as spectroscopically, electrochemically and structurally characterized. DFT calculations predicted a high value of the electron affinity (EA) and a low lying LUMO level for these compounds....
Article
Full-text available
A novel one-step solution based technique to produce bi-functional semiconductor–dielectric composites for organic field effect transistor (OFET) applications has been developed. By changing the parameters and components, one can produce the composites with semiconductors on the top or at the bottom of the polymer film suitable for fabrication of O...
Article
Electronic conductivity in polymer conductors, semiconductors, and insulators is described in terms of mechanisms of charge carrier generation and transport. Basic models of conductivity, specific to different classes of polymer materials (with special emphasis on semiconducting, photoconducting, and conducting polymers), are presented and their im...
Article
In organic electronics solution-processable n-channel field-effect transistors (FETs) matching the parameters of the best p-channel FETs are needed. Progress toward the fabrication of such devices is strongly impeded by a limited number of suitable organic semiconductors as well as by the lack of processing techniques that enable strict control of...
Article
Transparent and air stable organic field effect transistors with ordered layers of dibenzo[d,d]thieno[3,2-b;4,5-b 0 ]dithiophene obtained from solution a b s t r a c t In a search for solution processable and stable p-type semiconductors an analogue of pentacene namely dibenzo[d,d]thieno[3,2-b;4,5-b 0 ]dithiophene (DBTDT) – was tested as an active...
Article
We have studied the structure, microhardness, and thermomechanical properties of poly(styrenebutylacrylate)– magnetite hybrid composites, obtained by the method of suspension polymerization. We have established that composite grains are not susceptible to aggregation and have a spherical shape. By means of Raman spectroscopy, we have detected that,...
Article
We report on the equivalent circuit modeling of the relaxation behavior of an optically-excited thick poly(3-hexylthiophene) (P3HT) film by means of impedance spectroscopy. Fabricated metal-semiconductor-metal devices with Au electrodes showed a nearly perfect ohmic behavior under ambient conditions. Impedance measurements on illuminated P3HT devic...
Article
We report a comparative study of OFET devices based on zone-cast layers of three tetrathiafulvalene (TTF) derivatives in three configurations of electrodes in order to determine the best performing geometry. The first testing experiments were performed using SiO2/Si substrates. Then the optimum geometry was employed for the preparation of flexible...
Article
The phase transition observed by various methods in poly(vinyl methyl ether)/water systems at around 18 degrees C has been assigned by some investigators to the pre-melting of water and by others to a glass transition of the polymer. In this study, broadband dielectric spectroscopy and temperature modulated differential scanning calorimetry were us...
Article
A new theoretical insight into the process of free charge carrier photogeneration in polymers is introduced, based on the fact that increasing intensity of electric field may change the charge dynamics during the dissociation process of geminate pairs of photogenerated charge carriers. These changes are reflected in the model by the variation of in...
Article
New tetraester derivatives of 1,4,5,8-tetraazaanthracene have been prepared and characterized by spectroscopic and electrochemical techniques. The LUMO level of the compounds is close to -4 eV (the so-called air operating stability border in n-channel field effect transistors). Tetraesters were obtained with reasonable yields without the necessity...