@incollection{MuellerBurkovMandaletal., author = {M{\"u}ller, Klaus and Burkov, Yevgen and Mandal, Dipankar and Henkel, Karsten and Paloumpa, Ioanna and Goryachko, Andriy and Schmeißer, Dieter}, title = {Microscopic and spectroscopic characterization of interfaces and dielectric layers for OFET devices}, series = {Organic Electronics : structural and Electronic Properties of OFETs}, booktitle = {Organic Electronics : structural and Electronic Properties of OFETs}, editor = {W{\"o}ll, Christof}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-40810-8}, pages = {445 -- 468}, language = {en} } @article{MuellerBurkovSchmeisser, author = {M{\"u}ller, Klaus and Burkov, Yevgen and Schmeißer, Dieter}, title = {Photo-Emission-Electron-Microscopy for Characterization of an Operating Organic Electronic Device}, language = {en} } @misc{MuellerGoryachkoBurkovetal., author = {M{\"u}ller, K. and Goryachko, Andriy and Burkov, Yevgen and Schwiertz, Carola and Ratzke, Markus and K{\"o}ble, J. and Reif, J{\"u}rgen and Schmeißer, Dieter}, title = {Scanning Kelvin probe and photoemission electron microscopy of organic source-drain structures}, series = {Synthetic Metals}, volume = {146}, journal = {Synthetic Metals}, number = {3}, pages = {377 -- 382}, language = {en} } @inproceedings{MuellerMilkoBurkovetal., author = {M{\"u}ller, Klaus and Milko, Sergey and Burkov, Yevgen and Schmeißer, Dieter}, title = {Mischkristalle des Systems ZnS-CuInS2 f{\"u}r multispektrale Solarzellen}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {Wir haben CuInS2 (CIS) unterschiedlicher Herstellung (Koverdampfung, Sputtern, Pulsed Laser Deposition, CIS auf Kupferband aufgebracht) untersucht. Neben Tiefenprofilen (durch Sputtern) der Elementverteilung dieser Proben wurden der Einfluss der Temperatur, von aufgedampftem Kupfer und Indium, ebenfalls bei verschiedenen Temperaturen, auf das Verhalten der St{\"o}chiometrie mit spektroskopischen Methoden (XPS, UPS) studiert. Parallel dazu wurde das Verhalten von im Vakuum aufgedampften ZnS und die entsprechenden Oberfl{\"a}chenreaktionen in Abh{\"a}ngigkeit von der Temperatur untersucht und charakterisiert, so dass Aussagen {\"u}ber die Optimierung und Anpassung von Pr{\"a}parationsbedingungen und Parametern zur Herstellung von erstens reinem CIS und zweitens von Mischkristallen des Typs Zn2-xCuxInxS2 m{\"o}glich werden. Zwischen den beiden Endgliedern ZnS und CuInS2 besteht bis auf einen Phasen{\"u}bergang bei etwa 80\% CIS l{\"u}ckenlose Mischbarkeit gem{\"a}ss Zn2-xCuxInxS2 (Bente: Chem.Erde (1991)). Die elektronische Bandl{\"u}cke dieser Mischkristalle l{\"a}sst sich im Vergleich zu reinem CuInS2 in einem Bereich von 3,67 eV (ZnS) bis 1,55 eV (CuInS2) variieren. Damit besteht die M{\"o}glichkeit, durch kontrollierte {\"A}nderung der Zusammensetzung der Schichten die Effizienz von Solarzellen aus diesem Material zu optimieren.}, language = {de} } @misc{HenkelTorcheSohaletal., author = {Henkel, Karsten and Torche, Mohamed and Sohal, Rakesh and Karavaev, Konstantin and Burkov, Yevgen and Schwiertz, Carola and Schmeißer, Dieter}, title = {Pr-O-Al-N dielectrics for metal insulator semiconductor stacks}, language = {en} } @misc{WehnerKarpitschkaBurkovetal., author = {Wehner, Stefan and Karpitschka, Stefan and Burkov, Yevgen and Schmeißer, Dieter and K{\"u}ppers, J{\"u}rgen and Brand, Helmut R.}, title = {Stochastic aspects of pattern formation during the catalytic oxidation of CO on Pd(111)}, language = {en} } @misc{HenkelBurkovKaravaevetal., author = {Henkel, Karsten and Burkov, Yevgen and Karavaev, Konstantin and Torche, Mohamed and Schwiertz, Carola and Schmeißer, Dieter}, title = {Optimization of the AION buffer layer for PrxOy/Si stacks}, language = {de} } @article{SchmeisserBurkovPaloumpaetal., author = {Schmeißer, Dieter and Burkov, Yevgen and Paloumpa, Ioanna and Mandal, Dipankar and Henkel, Karsten}, title = {Microscopic and Spectroscopic Characterization of Interfaces and Dielectric Layers for OFET Devices}, language = {en} } @inproceedings{HenkelBurkovBergholzetal., author = {Henkel, Karsten and Burkov, Yevgen and Bergholz, Matthias and Karavaev, Konstantin and Sohal, Rakesh and Torche, Mohamed and Schmeißer, Dieter}, title = {Al-Oxynitride as a buffer layer for high-k dielectrics}, series = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, pages = {161 -- 162}, language = {en} } @inproceedings{BurkovHenkelSchmeisser, author = {Burkov, Yevgen and Henkel, Karsten and Schmeißer, Dieter}, title = {X-ray photoemission spectroscopy of Aluminium Oxynitride on Si(001) and the rise as buffer layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 243}, abstract = {Praseodymium oxide (PrxOy) is one of the candidate as high-k transistor gate dielectrics, but aluminium oxynitride (AlxONy) as buffer layer is needed to prevent diffusions from the silicon into PrxOy and to hinder charge injection from the semiconductor into the insulator. The thermal stability and thickness dependence of aluminum oxynitride (AlxONy) has been investigated by synchrotron radiation photoemission spectroscopy (SR-PES). AlxONy layers were prepared by low energy ion-beam assisted deposition (LE-IBAD) at room temperature on a silicon substrate cleaned with HF-acid. Aluminium oxynitride is stable till 800∘C. From photoemission spectra we can assess that silicon oxynitride is built as first and then the growth of AlxONy follows. Resonant inelastic X-ray scattering measurements with synchrotron radiation have been performed. The combination of X-ray absorption spectroscopy (XAS) and RIXS make possible to determinate the band gap of AlxONy.}, language = {en} } @article{HenkelKaravaevTorcheetal., author = {Henkel, Karsten and Karavaev, Konstantin and Torche, Mohamed and Schwiertz, Carola and Burkov, Yevgen and Schmeißer, Dieter}, title = {Al-Oxyxynitride interfacial layer investigations for PrXOY on SiC and Si}, language = {en} } @inproceedings{MuellerBurkovSchmeisser, author = {M{\"u}ller, Klaus and Burkov, Yevgen and Schmeißer, Dieter}, title = {Spectromicroscopic Characterisation of All Polymer Transistor Structures}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {In order to optimize organic field effect transistors, the characterization of surfaces in terms of their roughness or chemical composition is very important. We report on high resolution spectromicroscopic mapping of organic thin film transistors by photoemission electron microscopy (PEEM). It was shown that PEEM is a useful technique to characterize the surface morphology (roughness), the chemical homogeneity or the composition of structures in between the source and drain electrodes. Mapping of surface potentials, especially at the interface electrode/channel is possible. We compare different preparation methods and the characterization at applied voltages is also shown. The transistors itself were prepared by a new low cost method. The electrodes for source and drain have been prepared by a plotting method with colloidal graphite or carbon black as the conducting material. P3HT was used as active layer and has been prepared by spin coating.}, language = {en} } @article{Burkov, author = {Burkov, Yevgen}, title = {Dielectric Buffer Layer (Aluminium Oxynitride/AlON) for Ultrathin High-k Materials}, editor = {Vierhaus, Heinrich Theodor}, language = {en} } @inproceedings{SeifarthBurkovSchmeisseretal., author = {Seifarth, Olaf and Burkov, Yevgen and Schmeißer, Dieter and Sydorenko, Alexander and Krenek, Radim and Stamm, Manfred}, title = {Photoelectron spectroscopy and microscopy on magnetic nano particles embedded into block copolymers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {The formation of metallic nano particles stored in thin films of block copolymers has been investigated by means of synchrotron radiation based photoemission spectroscopy (PES) and microscopy (PEEM). Empty channels in poly(styrene-block-4-vinylpyridine) copolymer with diameters of tens of nanometers filled with CrO2, Cr2O3 and Ni provide ideal bases for performing electron spectroscopy with energy and lateral resolution on magnetic nano particles. We present UPS, XPS, NEXAFS spectra and PEEM images on and off the C 1s, Cr 2p, Ni 2p resonances and discuss the geometric and electronic structure of such compounds. The synchrotron radiation was delivered from the U49/2 beamline at BESSY II.}, language = {en} } @article{HenkelSohalSchmeisseretal., author = {Henkel, Karsten and Sohal, Rakesh and Schmeißer, Dieter and Schwiertz, Carola and Burkov, Yevgen and Torche, Mohamed}, title = {Al-oxynitride buffer layer facilities for PrOx/SiC interfaces}, language = {en} } @misc{SeifarthBurkovSchmeisseretal., author = {Seifarth, Olaf and Burkov, Yevgen and Schmeißer, Dieter and Stamm, Manfred}, title = {Metallic nickel nanorod arrays embedded into ordered block copolymer templates}, series = {Thin Solid Films}, volume = {515}, journal = {Thin Solid Films}, number = {16}, issn = {0040-6090}, pages = {6552 -- 6556}, language = {en} } @inproceedings{MuellerBurkovSchmeisser, author = {M{\"u}ller, Klaus and Burkov, Yevgen and Schmeißer, Dieter}, title = {Surface potential profiling on organic thin film transistors by photoemission-electron-microscopy (PEEM)}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {Surface potential imaging with Photoemission-electron-microskopy (PEEM) in high lateral resolution is introduced as a new tool for the characterisation of organic transistor structures. We use source-drain- electrode structures of different organic materials like carbon-black or graphite plotted on a printing foil. Semiconducting regioregular Poly(3-Hexylthiophene-2,5-diyl) (P3HT) was deposited by spin coating. For our measurements we used radiation of a standard high pressure Hg-lamp (4,9 eV) and synchrotron radiation at the BESSYII-U49/2 beam line. In contrast to Kelvin-AFM measurements of the surface potential, PEEM enables a simultaneous analysis of chemical composition by photoelectron spectroscopy. UPS, for example, at zero potential gives information on chemical homogeneity of the organic semiconductor in lateral resolution. PEEM images at applied voltages, compared with UPS-spectra, gives informations on doping profiles in the semiconductor, for example. In conclusion, PEEM should be a complementary method for characterisation of the surface potential with Kelvin-AFM. In addition, PEEM gives opportunities for measurements of chemical composition in the working state of the transistor (applied voltages).}, language = {en} } @inproceedings{HenkelSohalTorcheetal., author = {Henkel, Karsten and Sohal, Rakesh and Torche, Mohamed and Schwiertz, Carola and Burkov, Yevgen and Schmeißer, Dieter}, title = {PrOx/AlON stacks as a high-k candidate on SiC}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 215}, abstract = {We study the chemical stability and electrical properties of Pr-oxides-SiC MIS stacks. In MISFET devices for high power applications the electric field scaling at the interface between semiconductor and insulator is determined by the ratio of their permittivity values. A high-k material can be used to optimize the performance of such devices. In previous studies we had to understand that the chemical reactivity of the PrOx/SiC interface causes a destructive interaction yielding silicate and graphite formation as well as poor electrical performance after direct deposition of PrOx onto SiC. Therefore we introduced an additional chemically inert layer and in this contribution we focus on PrOx/AlON as a suitable insulator stack. In our spectroscopic investigations we recognized a stable AlON/3C-SiC interface even for annealing steps up to 900∘C. First electrical characterizations are performed on Si substrates and we find a strong improvement in the leakage current by several orders of magnitude down to values of 10-7 A/cm2 at an EOT of 4nm and interface state densities of mean values of 5*1011/eVcm2. We also report on our ongoing electrical characterization of such stacks on SiC substrates. This work is supported by Deutsche Forschungsgemeinschaft within priority program 1157 (DSCH 745/9-2).}, language = {en} } @inproceedings{SidorenkoTokarevKreneketal., author = {Sidorenko, Alexander and Tokarev, Igor and Krenek, Radim and Burkov, Yevgen and Schmeißer, Dieter and Minko, S. and Stamm, Manfred}, title = {Generation of Nanostructured Materials from Thin Films of Block Copolymer Assembles}, series = {Nano-architectured and manostructured materials, fabrication, control and properties, EUROMAT 2003}, booktitle = {Nano-architectured and manostructured materials, fabrication, control and properties, EUROMAT 2003}, editor = {Champion, Yannick and Fecht, Hans-J{\"o}rg}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {3-527-31008-8}, pages = {143 -- 150}, language = {en} } @article{PaloumpaYfantisHoffmannetal., author = {Paloumpa, Ioanna and Yfantis, Alexandros D. and Hoffmann, Patrick and Burkov, Yevgen and Yfantis, Alexandros D. and Schmeißer, Dieter}, title = {Mechanisms to inhibit corrosion of Al alloys by polymeric conversion coatings}, abstract = {We introduce a recently developed novel polypyrrole-based coating, which can be formed on the aluminium surface from an aqueous pyrrole solution of fluorozirconic and fluorotitanic acid neutralised with zinc oxide. The composite layer consists of polypyrrole (Ppy) chemisorbed on titanium and zinc oxides and exhibits advanced corrosion resistance. For the investigation of the structure and the corrosion mechanism of the composite corrosion resistant layer we use a photo-electron emission microscope (PEEM). PEEM is especially suitable because it can deliver topographic contrast as well as elemental contrast and chemical information in connection with a variable X-ray source. Additionally, in order to investigate further the corrosion mechanism, but also the role of the alloy in the corrosion process, we examine the aluminium samples with SEM/EDX. The structure of the corrosion resistant layer was investigated before and after accelerated corrosion tests. Our results pointed out the important role of titanium oxide and zinc in the corrosion resistance of our Ppy coating on aluminium.}, language = {en} } @article{GoryachkoPaloumpaBeuckertetal., author = {Goryachko, Andriy and Paloumpa, Ioanna and Beuckert, Guido and Burkov, Yevgen and Schmeißer, Dieter}, title = {The Interaction of Pr2O3 with 4H-SiC(0001)surface}, series = {Physica status solidi / C}, volume = {1}, journal = {Physica status solidi / C}, number = {2}, issn = {1610-1634}, pages = {265 -- 268}, abstract = {Praseodymium oxide (Pr2O3) as a hetero-oxide on SiC(0001) represents a promising semiconductor / high-K dielectric material combination. We prepared thin films (<3 nm) of Pr2O3 on 4H-SiC(0001) surfaces by a wet chemical process involving aqueous solutions of Pr(NO3)3. Synchrotron radiation photoelectron spectroscopy (SR-PES) is used to study the chemical composition of these films after deposition and annealing in 300-900 \%B0C range. The Si2p and C1s core level emissions are analysed in detail and reveal that praseodymium-silicate is formed at the interface. Our data are compared to corresponding studies of the Pr2O3 interaction with Si(001) surfaces.}, language = {en} } @article{MuellerScheerSchmeisseretal., author = {M{\"u}ller, Klaus and Scheer, R. and Schmeißer, Dieter and Burkov, Yevgen}, title = {Preparation of stoichiometric CuInS2-Surfaces}, series = {Thin Solid Films}, volume = {451-452}, journal = {Thin Solid Films}, issn = {0040-6090}, pages = {120 -- 123}, language = {en} } @misc{MuellerBurkovSchmeisser, author = {M{\"u}ller, Klaus and Burkov, Yevgen and Schmeißer, Dieter}, title = {PEEM and my-NEXAFS of Cu-In-S2-surfaces}, series = {Thin Solid Films}, volume = {431-432}, journal = {Thin Solid Films}, issn = {0040-6090}, pages = {307 -- 311}, abstract = {Polycrystalline CuInS2 samples are an ideal system for photoemission electron microscope studies. The polycrystalline grains have a diameter of approximately 5 small mu, Greekm and the system is expected to be highly inhomogeneous because of the existence of many sub-phases. We used a recently established procedure to reproducibly obtain stoichiometric CuInS2-surfaces and follow the changes in the morphology, the elemental inhomogeneous distribution, and the development of the electronic structure upon its preparation. We find that the individual grains trend to coagulate, the surface composition becomes more homogeneous, and identify characteristic features of the unoccupied DOS.}, language = {en} } @article{SchmeisserPaloumpaHoffmannetal., author = {Schmeißer, Dieter and Paloumpa, Ioanna and Hoffmann, Patrick and Burkov, Yevgen and Yfantis, Alexandros D. and Yfantis, Alexandros D.}, title = {Preventing Corrosion of Aluminium Alloys by Polymeric Coatings}, abstract = {Aluminium is a material of everyday use in many applications,like automobile,aero-space or cookware,due to its specialproperties (low density,low weight,strength,easy to form and cast,abundance etc).Although aluminium is a reactive metal,italso has a significant corrosion resistance because of a thin,protective oxide layer which is generally stable in air and aqueous solutions.However,pores within the oxide film and other defects caused from alloying elements can lead to local corrosion and the formation of pits.}, language = {en} } @misc{TokarevKrenekBurkovetal., author = {Tokarev, Igor and Krenek, Radim and Burkov, Yevgen and Schmeißer, Dieter and Sidorenko, Alexander and Minko, Sergiy and Stamm, Manfred}, title = {Microphase separation in thin films of poly(styrene-block-4-vinylpyridine) Copolymer-2-(4-Hydroxybenzeneazo) benzoic Acid Assembly}, series = {Macromolecules}, volume = {38}, journal = {Macromolecules}, number = {2}, issn = {1520-5835}, pages = {507 -- 516}, abstract = {The fine structure of thin films of poly(styrene-block-4-vinylpyridine) copolymer-2-(4'-hydroxybenzeneazo)benzoic acid (PS-PVP+HABA) assembly has been studied using the combination of atomic force microscopy, ellipsometry, X-ray reflectivity, GISAXS, XPS, and XPEEM. The films consist of cylindrical nanodomains formed by PVP+HABA associates surrounded by PS matrix. Alignment of the domains can be switched upon exposure to vapors of different solvents from the parallel to perpendicular orientation and vice versa with respect to the surface plane. Swelling in 1,4-dioxane leads the system from the cylindrical to the spherical morphology. Solvent evaporation results in a shrinkage of the matrix in the vertical direction and subsequent merging of the spheres into the perpendicularly aligned cylinders. The cylinders form a regular hexagonal lattice with a spatial period of 25.5 nm. On the other hand, vapors of chloroform induce in-plane alignment. The films consist of parallel layers of the cylinders separated by PS matrix and demonstrate the fingerprint-like structure. The nanocylinders of PVP+HABA are packed into a distorted hexagonal lattice exhibiting 31 nm in plane and 17 nm vertical periodicity. In both cases a thin wetting layer is found at the polymer-substrate interface. The free surface is enriched with PS.}, language = {en} } @misc{MuellerGoryachkoBurkovetal., author = {M{\"u}ller, Klaus and Goryachko, Andriy and Burkov, Yevgen and Schwiertz, Carola and Ratzke, Markus and K{\"o}ble, J. and Reif, J{\"u}rgen and Schmeißer, Dieter}, title = {Scanning Kelvin Probe Microscopy and Photoemission electron microscopy of organic source-drain structures}, series = {Synthetic Metals}, volume = {146}, journal = {Synthetic Metals}, number = {3}, issn = {0379-6779}, pages = {377 -- 382}, abstract = {n order to optimize organic field effect transistors (OFETs), the characterisation of active-layer surfaces in terms of their roughness, chemical composition and distribution of surface potentials is important. We report on high-resolution microscopic mapping of organic source-drain structures with P3HT as the semiconductor by scanning Kelvin probe microscopy (SKPM) and photoemission electron microscopy (PEEM). It was shown that PEEM is able to characterise the surface morphology (roughness), the chemical homogeneity and the composition of organic structures. The two-dimensional mapping of surface potentials by SKPM with applied source-drain voltages is shown to be an important ingredient of OFETs failure mode analysis.}, language = {en} } @article{Burkov, author = {Burkov, Yevgen}, title = {Comparison on Focus-PEEM and Elmitec-PEEM}, language = {en} } @article{SeifarthBurkovGoryachkoetal., author = {Seifarth, Olaf and Burkov, Yevgen and Goryachko, Andriy and Schmeißer, Dieter and Sydorenko, Alexander and Krenek, Radim and Stamm, Manfred}, title = {Photoelectron spectroscopy and microscopy on Cr nano particels embedded into block copolymers}, language = {en} } @misc{SidorenkoTokarevKreneketal., author = {Sidorenko, Alexander and Tokarev, Igor and Krenek, Radim and Burkov, Yevgen and Schmeißer, Dieter and Stamm, Manfred}, title = {XPEEM investigations of 2D hierachical array of Ni nanorods using block copolymer templates}, language = {de} } @article{MuellerHoffmannMilkoetal., author = {M{\"u}ller, Klaus and Hoffmann, Patrick and Milko, S. and Burkov, Yevgen and Schmeißer, Dieter}, title = {PEEM and µ-NEXAFS of Cu-In-S-Surfaces}, abstract = {The composition of CuInS2-films tends to differ from the ideal ratio of 1:1:2. A molecularlyvariation of dm=[Cu]/[In]-1 not equal 0 occurs due to the formation of binary phases as segregation's at the surface, as crystallites in the bulk of the film or at the surface of grains [1]. Furthermore, the range of homogeneity of the phase CuInS2 is relatively large caused by a low enthalpy of formation of defects like Cu-vacancies [2]. Segregation's at surfaces can be removed by KCN etching or by an electrochemical process [3, 4] We investigated the effect of an in-situ-heat-treatment of samples, prepared in the Cu-rich regime with additional amounts of copper, deposited on the surface of the Cu-In-S-films.We used Cu-In-S-films on molybdenum, prepared from precursors of Cu/In and a following reactive annealing-process in a sulphur-atmosphere. The experiments were performed as follows: The surface of the films was cleaned in situ to remove CuS-Phases by Argon-bombardment. The thin layers of additional Copper were prepared by evaporation of copper metal in Knudsen-cells. The thickness of this copper-films is in the range of monolayers, revealed by a calibration with copper on iron-substrates. After this deposition the samples were heated up to several temperatures (up to 550 ºC) for ten minutes, respectively. Here the molybdenum back-contact was used as electrical heater.}, language = {en} }