TY - JOUR A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Back-propagation based neural network with a two sensor system for monitoring of carbon dioxide and relative humidity Y1 - 2002 ER - TY - RPRT A1 - Schwiertz, Carola A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter A1 - Kamieth, P. A1 - Schnegber, P. T1 - Aufbau eines Sensorarrays zur Detektion von umwelt- und tierphysiologisch relevanten Komponenten Y1 - 2001 ER - TY - RPRT A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schwiertz, D. A1 - Schmeißer, Dieter A1 - Kamieth, P. A1 - Schengber, P. T1 - Gezielte Entwicklung von Sensormaterialien und Sensoren zur spezifischen Detektion von schwefel- und stickstoffhaltigen Stoffgruppen Y1 - 2001 ER - TY - JOUR A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schwiertz, B. A1 - Elling, B. A1 - Danz, R. A1 - Büchtemann, A. A1 - Straube, Oliver A1 - Schmeißer, Dieter T1 - Kraftsensoren aus Polymerfolien-Piezoelektrische Polymersensoren für Hochdruckanwendungen Y1 - 2001 ER - TY - RPRT A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Oprea, A. A1 - Appel, Günter A1 - Schmeißer, Dieter A1 - Frandsen, W. A1 - Schölzel, Mario T1 - Entwicklung von Sensoren mit Elektroden aus leitfähigen Polymeren Y1 - 2000 N1 - Teilbericht 16SV335/7 im Gemeinsamen Abschlussbericht zum Verbundprojekt "Sensoren mit mikrostrukturierten Elektroden aus leitfähigen Polymeren", März 2000, Kurzfassung ER - TY - JOUR A1 - Appel, Günter A1 - Mikalo, Ricardo Pablo A1 - Henkel, Karsten A1 - Oprea, A. A1 - Yfantis, Alexandros D. A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Polymeric Electrodes Y1 - 2000 ER - TY - JOUR A1 - Oprea, A. A1 - Henkel, Karsten A1 - Oehmgen, R. A1 - Appel, Günter A1 - Schmeißer, Dieter A1 - Lauer, H. A1 - Hausmann, P. T1 - Increased sensor sensitivities obtained by polymer coated quartz microbalances Y1 - 1999 ER - TY - GEN A1 - Friedrich, Daniel A1 - Henkel, Karsten A1 - Richter, Matthias A1 - Schmeißer, Dieter T1 - Fullerenol as probed by Synchrotron X-Ray Photoemission and Absorption Spectroscopy Y1 - 2011 ER - TY - CHAP A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Control of the Crystalline Polymorph, Molecular Dipole and Chain Orientations in P(VDF-HFP) for High Electrical Energy Storage Application T2 - International Conference on Nanoscience, Technology and Societal Implications (NSTSI), 2011 Y1 - 2012 SN - 978-1-4577-2035-2 U6 - https://doi.org/10.1109/NSTSI.2011.6111801 PB - IEEE ER - TY - GEN A1 - Klocek, Jolanta A1 - Henkel, Karsten A1 - Kolanek, Krzysztof A1 - Broczkowska, K. A1 - Schmeißer, Dieter A1 - Miller, M. A1 - Zschech, Ehrenfried T1 - Studies of the chemical and electrical properties of fullerene and 3-aminopropyltrimethoxysilane based low-k materials T2 - Thin Solid Films Y1 - 2012 SN - 0040-6090 VL - 520 IS - 7 SP - 2498 EP - 2504 ER - TY - GEN A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - The electroactive Beta-phase formation in Poly(vinylidene fluoride) by gold nanoparticles doping T2 - Materials Letters Y1 - 2012 SN - 0167-577X IS - 73 SP - 123 EP - 125 ER - TY - GEN A1 - Klocek, Jolanta A1 - Henkel, Karsten A1 - Kolanek, Krzysztof A1 - Zschech, Ehrenfried A1 - Schmeißer, Dieter T1 - Annealing influence on siloxane based materials incorporated with fullerenes, phthalocyanines and silsesquioxanes T2 - BioNanoScience Y1 - 2012 SN - 2191-1630 VL - 2 IS - 1 SP - 52 EP - 58 ER - TY - GEN A1 - Klocek, Jolanta A1 - Henkel, Karsten A1 - Kolanek, Krzysztof A1 - Zschech, Ehrenfried A1 - Schmeißer, Dieter T1 - Spectroscopic and capacitance-voltage characterization of thin aminopropylmethoxysilane films doped with copper phthalocyanine, tris(dimethylvinylsilyloxy)-POSS and fullerene cages T2 - Applied surface science Y1 - 2012 SN - 0169-4332 VL - 258 IS - 10 SP - 4213 EP - 4221 ER - TY - GEN A1 - Klocek, Jolanta A1 - Kolanek, Krzysztof A1 - Henkel, Karsten A1 - Zschech, Ehrenfried A1 - Schmeißer, Dieter T1 - Influence of the fullerene derivatives and cage polyhedral oligomeric silsesquioxanes on 3-aminopropyltrimethoxysilane based hybrid nanocomposites chemical, morphological and electrical properties T2 - Journal of Physics and Chemistry of Solids N2 - In this study we produced 3-aminopropyltrimethoxysilane based hybrid nanocomposites using fullerene derivative [6,6]–phenyl–C61–butyric acid methyl ester (PCBM) as nanodopants. Additionally, we modified obtained material with incompletely condensed cage polyhedral oligomeric silsesqiuox-anes (POSS) in order to improve its properties. Thin films were deposited by means of the spin-coating method. The films were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and capacitance–voltage (CV) measurements. We observed that a properly chosen PCBM concentration may be a crucial factor to obtain high quality APTMS based films by the spin-coating technique. XPS revealed the presence of the C-NH-C species within POSS containing films indicating chemical interaction between the amino group of APTMS and the POSS molecules. AFM results suggest that at high POSS monomer concentration in the range of 1% the creation of fractal-shaped aggregates takes place. The CV characterization of the samples exhibits a decrease of the APTMS based films dielectric constant due to the POSS and PCBM contribution. The combination of the applied methods delivers complementary information concerning the properties of the analyzed films. KW - low-k KW - fullerene KW - aminopropyltrimethoxysilane KW - silsesqiuoxane KW - X-ray photoelectron spectroscopy (XPS) KW - Atomic force microscopy (AFM) KW - Capacitance voltage (CV) Y1 - 2013 U6 - https://doi.org/10.1016/j.jpcs.2012.08.013 SN - 0022-3697 VL - 74 IS - 1 SP - 135 EP - 145 ER - TY - GEN A1 - Mandal, Dipankar A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - The effect of X-ray photoelectron spectroscopy measurement on P(VDF-TrFE) copolymer thin films T2 - Applied Surface Science N2 - The impact of prolonged X-ray irradiation during X-ray photoelectron spectroscopy (XPS) measurement was investigated on poly(vinylidene-trifluoroethylene) (P(VDF-TrFE)) thin films. It was observed that prolonged X-ray irradiation can accelerate the crosslinking of P(VDF-TrFE) and diminish the ferroelectric phase. Fourier transform infrared spectroscopy (FT-IR) data indicate that the ferroelectric phase diminishes completely after 360 kJ of X-ray irradiation dose and it induces the paraelectric phase. In this work, the main emphasis was given to the optimization of the X-ray irradiation dose during XPS measurements to maintain the ferroelectric phase within the copolymer films. KW - P(VDF-TrFE) copolymer thin film KW - XPS measurement KW - X-ray irradiation KW - Ferroelectric to paraelectric phase transformation Y1 - 2012 U6 - https://doi.org/10.1016/j.apsusc.2012.07.144 SN - 0169-4332 SN - 1873-5584 IS - 261 SP - 209 EP - 213 ER - TY - CHAP A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Das, Suken A1 - Schmeißer, Dieter ED - Heber, Jörg ED - Schlom, Darrell ED - Tokura, Yoshinori ED - Waser, Rainer ED - Wuttig, Matthias T1 - Control of β- and γ-Phase formation in electroactive P(VDF-HFP) films by silver nano-particle doping T2 - Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany KW - P(VDF.HFP) KW - electroactive phase KW - nanoparticle doping KW - FTIR Y1 - 2012 SN - 978-3-527-41191-7 U6 - https://doi.org/10.1002/9783527667703.ch69 SP - 640 EP - 641 PB - Wiley-VCH CY - Weinheim ER - TY - THES A1 - Henkel, Karsten T1 - Electrical Investigations on Praseodymium Oxide/Aluminum Oxynitride Containing Metal-Insulator-Semiconductor Stacks and on Metal-Ferroelectric-Insulator-Semiconductor Structures Consisting of Poly[vinylidene fluoride trifluoroethylene] N2 - In this thesis electrical characterizations on metal-insulator-semiconductor (MIS) and metal-ferroelectric-insulator-semiconductor (MFIS) stacks are presented. The results are discussed in terms of the increase of the performance of these stacks in order to optimize the characteristics of devices like the field effect transistor (FET) for logic applications and the ferroelectric field effect transistor (FeFET) for non-volatile and non-destructive readout memory applications. Therefor, two material classes are investigated. Firstly, this work focuses on praseodymium oxide (PrxOy) films as a high-kmaterial on silicon (Si) and silicon carbide in MISsamples. In particular the improvement of the performance by the introduction of an aluminum oxynitride buffer layer, which acts as an interdiffusion barrier and reduces the leakage current, the interface state density and the equivalent oxide thickness, is demonstrated. Secondly, in this work the very attractive ferroelectric material poly[vinylidene fluoride trifluoroethylene] (P[VDF/TrFE]) is introduced in MFIS stacks on Si. The way of successive improvements of the MFIS stack is extensively discussed. Here, the optimization of the preparation of the samples as well as of the layer parameters in the sequence of the MFIS stacks is depicted. An improved long time stability of the memory functionof the MFIS stack with a partially optimized layer sequence is exhibited. The electrical results are correlated to spectroscopic findings on both material systems. Strong interfacial reactions between the PrxOy and Si as well as between the aluminum electrode and the P[VDF/TrFE] layer are observed. For both systems the importance of a buffer layer is discussed and its optimization is addressed, too. On both systems a very nice, as consistent, chain of improvements is shown caused by the spectroscopic controlled preparation combined with electrical measurements in order to obtain the functionality of a given material system. KW - Pr2O3 KW - P(VDF-TrFE) KW - capacitance-voltage KW - conductance-voltage KW - current-voltage KW - dielectric properties KW - high-k KW - feFET Y1 - 2009 SN - 978-3-8322-8404-6 PB - Shaker CY - Aachen ER - TY - GEN A1 - Haeberle, Jörg A1 - Henkel, Karsten A1 - Gargouri, Hassan A1 - Naumann, Franziska A1 - Gruska, Bernd A1 - Arens, Michael A1 - Tallarida, Massimo A1 - Schmeißer, Dieter T1 - Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al2O3-films T2 - Beilstein Journal of Nanotechnology N2 - We report on results on the preparation of thin (<100 nm) aluminum oxide (Al2O3) films on silicon substrates using thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) in the SENTECH SI ALD LL system. The T-ALD Al2O3layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4” wafers and correlatethem to X-ray photoelectron spectroscopy (XPS) results. The 200°C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films. KW - Al2O3 KW - ALD KW - ellipsometry KW - PE-ALD KW - XPS Y1 - 2013 U6 - https://doi.org/10.3762/bjnano.4.83 SN - 2190-4286 VL - 2013 IS - 4 SP - 732 EP - 742 ER - TY - GEN A1 - Henkel, Karsten A1 - Gargouri, Hassan A1 - Gruska, Bernd A1 - Arens, Michael A1 - Tallarida, Massimo A1 - Schmeißer, Dieter T1 - Capacitance and conductance versus voltage characterization of Al2O3 layers prepared by PE-ALD at 25°C ≤ T ≤ 200°C T2 - Journal of Vacuum Science and Technology A N2 - In this work, plasma enhanced atomic layer deposited (PE-ALD) samples were prepared at substrate temperatures in the range between room temperature (RT) and 200 °C and investigated by capacitance–voltage and conductance–voltage recordings. The measurements are compared to standard thermal atomic layer deposition (T-ALD) at 200 °C. Very low interface state density (D it) ~1011 eV−1 cm−2 could be achieved for the PE-ALD process at 200 °C substrate temperature after postdeposition anneal (PDA) in forming gas at 450 °C. The PDA works very effectively for both the PE-ALD and T-ALD at 200 °C substrate temperature delivering also similar values of negative fixed charge density (N fix) around −2.5 × 1012 cm−2. At the substrate temperature of 150 °C, highest N fix (−2.9 × 1012 cm−2) and moderate D it (2.7 × 1011 eV−1 cm−2) values were observed. The as deposited PE-ALD layer at RT shows both low D it in the range of (1 to 3) × 1011 eV−1 cm−2 and low N fix (−4.4 × 1011 cm−2) at the same time. The dependencies of N fix, D it, and relative permittivity on the substrate temperatures and its adjustability are discussed. KW - Atomic layer deposition (ALD) KW - Al2O3 KW - dielectric properties KW - interface state density KW - fixed oxide charge KW - permittivity Y1 - 2014 UR - http://link.aip.org/link/?JVA/32/01A107&aemail=author U6 - https://doi.org/10.1116/1.4831897 VL - 1 IS - 32 SP - 01A107-1 EP - 01A107-10 ER - TY - CHAP A1 - Henkel, Karsten A1 - Tallarida, Massimo A1 - Haeberle, Jörg A1 - Gargouri, Hassan A1 - Naumann, Franziska A1 - Gruska, Bernd A1 - Arens, Michael A1 - Schmeißer, Dieter ED - Glück, Bernhard K. ED - Schmidt, Sindy ED - Stein, Erhard ED - Raschke, Jörg-Uwe ED - Richter, Hans T1 - PE-ALD-Al2O3-Schichten für die Passivierung von Solarzellen T2 - Tagungsband Photovoltaik-Meeting: Anwendungen-Qualität-Perspektiven, Senftenberg, 16.04.2014 N2 - Dünne Al2O3-Schichten wurden bei Substrattemperaturen zwischen Raumtemperatur und 200°C mittels PE-ALD auf Si-Substraten abgeschieden und ellipsometrisch, spektroskopisch und elektrisch charakterisiert. Ihr Potenzial für die chemische und Feldeffektpassivierung der Oberflächenrekombination wird bewertet. KW - Al2O3 KW - Atomlagenabscheidung (ALD) KW - Passivierung KW - PE-ALD KW - negative fixe Oxidladungen Y1 - 2014 SP - 7 EP - 14 PB - Cottbus-Senftenberg CY - BTU ER - TY - GEN A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Improved performance of a polymer nanogenerator based on silver nanoparticles doped electrospun P(VDF–HFP) nanofibers T2 - Physical Chemistry Chemical Physics N2 - We report on the electrospinning of poly(vinylidene fluoride–hexafluoropropylene) [P(VDF–HFP)] nanofibers doped with silver nanoparticles for the preparation of a polymer based nanogenerator (PNG). It has been found that the yield of the piezoelectric phase is increased by the addition of silver nanoparticles. Furthermore, defects in the P(VDF–HFP) electrospun fibers are removed resulting in a significant enhancement in the output power of the PNG. A maximum generated PNG output voltage of 3 V with a current density of 0.9 μA cm−2 is achieved. KW - piezoelectric thin polymer film KW - FTIR KW - nanogenerator KW - PVDF KW - P(VDF-HFP) KW - nanofibers Y1 - 2014 U6 - https://doi.org/10.1039/C3CP55238A SN - 1463-9084 SN - 1463-9076 VL - 2014 IS - 16 SP - 10403 EP - 10407 ER -