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 - Philip, Shine A1 - Richter, Matthias A1 - Friedrich, Daniel A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Spectroscopic investigations of P3HT/PCBM films for organic BHJ solar cells T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - Investigations of the electronic structure and composition of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) based films using Near Edge X-Ray Absorption Fine Structure (NEXAFS) are presented. The measurements were performed at the U49/2-PGM2 beam line of BESSY II, Berlin recording TEY (total electron yield) and TFY (total fluorescence yield) data. Samples prepared by spin coating a mixture of P3HT dissolved in chloroform and PCBM dissolved in chlorobenzene onto ITO (indium tin oxide) coated glass slides were analyzed. Upon measuring the pure P3HT and PCBM, all reported excitations were observed, whereas the blended system is a weighted superposition of the related peaks. Analyzing the data we calculate the composition of the mixture. We also show angular dependent NEXAFS measurements of the P3HT/PCBM blend in order to measure the orientation and distribution of the P3HT polymer. Additionally, we show a new approach for organic solar cell application. BaTiO3 nanoparticles were incorporated as nanodispersion into the donor-acceptor blend or the ferroelectric copolymer poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) was spincoated as an ultrathin film below the blend. Y1 - 2010 SN - 0420-0195 SP - S. 153 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Kachel, Krzysztof A1 - Richter, Matthias A1 - Philip, Shine A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Performance of organic solar cells with a ferroelectric component T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - Charge dissociation and recombination are important factors for the efficiency of organic solar cells, even in blended systems of different polymers. As a new approach, the influence of additional blended ferroelectric nanoparticles on the solar cell performance is investigated. The ferroelectric dipole of the nanoparticle causes a local field, which could lead to a longer recombination time of the polaron pairs. As solar cell system we use bulk heterojunction cells or bilayer structures based on regioregular poly(3-hexylthiophene) (P3HT) as the donor and phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor molecule. As ferroelectric additive we use the ferroelectric copolymer poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) or BaTiO3. The copolymer is spincoated as ultrathin film of 20nm, whereas the BaTiO3 is incorporated as nanodispersion into the donor-acceptor blend. We present the solar cell parameters for the different geometries and ferroelectric materials as a function of ferroelectric content and of the alignment of the ferroelectric dipoles after application of an external electric field. Y1 - 2010 UR - http://www.dpg-verhandlungen.de/year/2010/conference/regensburg/part/cpp/session/27/contribution/6 SN - 0420-0195 SP - S. 153 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Matthias A1 - Müller, Klaus A1 - Philip, Shine A1 - Paloumpa, Ioanna A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Temperature dependence of organic solar cell parameters T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44 N2 - The influence of an annealing step on the parameters of bulk heterojunction organic solar cells is investigated. In order to fabricate the solar cells we use glass coated with ITO (Indiumtinoxide) as a substrate on which the active layer consisting of P3HT and PCBM is spincoated. Al-electrodes are evaporated on top of the active layer. We use PEDOT:PSS as buffer layer. Each sample is annealed at different temperatures for a short time. Between every temperature step the I-V characteristic of the cell is measured. The following parameters are derived afterwards: FF, Isc (density), Voc. Also the efficiency is estimated. The results show a maximum cell efficiency for drying at 100°C for 20sec. A further important step for preparation is the drying procedure of the PEDOT:PSS layer. Here an improvement of about 50% in cell efficiency is measured after drying at 50°C for 5 days under inert gas atmosphere. Y1 - 2009 UR - http://www.dpg-verhandlungen.de/year/2009/conference/dresden/part/syop/session/4/contribution/2 SN - 0420-0195 SP - S. 671 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Christian A1 - Lindemann, Jens A1 - Römer, Ronald A1 - Wolff, Matthias ED - Wirsching, Günther T1 - Das Labor für kognitive Systeme an der BTU Cottbus-Senftenberg T2 - Tagungsband, 26. Konferenz Elektronische Sprachsignalverarbeitung, 25.-27.03.2015, Eichstätt Y1 - 2015 SN - 978-3-95908-000-2 SP - 240 EP - 247 PB - TUDpress CY - Dresden ER - TY - GEN A1 - Reuter, Marvin A1 - Diehl, Katharina A1 - Richter, Matthias A1 - Sundmacher, Leonie A1 - Hövener, Claudia A1 - Spallek, Jacob A1 - Dragano, Nico T1 - A longitudinal analysis of health inequalities from adolescence to young adulthood and their underlying causes T2 - Advances in Lifecourse Research N2 - Research suggests that children of low-educated parents face greater health burdens during the passage from adolescence to young adulthood, as they are more likely to become low-educated themselves, establish behavioural and psychosocial disadvantages, or being exposed to unhealthy working conditions. However, studies examining the development and drivers of health inequalities during this particular life stage are limited in number and have produced varied results. This study investigates trajectories of self-rated health and overweight from 14 to 25 years of age, stratified by parental education, and explores the role of potential mediators (educational achievement, health behaviours, psychosocial factors, working conditions). We rely on prospective cohort data from the National Educational Panel Study (NEPS), a representative sample of 14,981 German ninth graders interviewed yearly from 2011 to 2021 (n = 90,096 person-years). First, we estimated random-effects growth curves for self-rated health and overweight over participants’ age and calculated the average marginal effect of high versus low parental education. Second, a series of simulation-based mediation analyses were performed to test how much of health inequalities were explained by children’s educational attainment (years of school education, years in university), health behaviours (smoking, alcohol, physical inactivity), psychosocial factors (number of grade repetitions, years in unemployment, chronic stress, self-esteem) and working conditions (physical and psychosocial job demands). We accounted for potential confounding by controlling for age, sex, migration background, residential area, household composition, and interview mode. Results show that higher parental education was related to higher self-rated health and lower probabilities of being overweight. Interaction between parental education and age indicated that, after some equalisation in late adolescence, health inequalities increased in young adulthood. Furthermore, educational attainment, health behaviours, psychosocial factors, and early-career working conditions played a significant role in mediating health inequalities. Of the variables examined, the level of school education and years spent in university were particular strong mediating factors. School education accounted for around one-third of the inequalities in self-rated health and one-fifth of the differences in overweight among individuals. Results support the idea that the transition to adulthood is a sensitive period in life and that early socio-economic adversity increases the likelihood to accumulate health disadvantages in multiple dimensions. In Germany, a country with comparatively low educational mobility, intergenerational continuities in class location seem to play a key role in the explanation of health inequalities in youth. KW - Health Inequalities KW - Adolescence KW - School to work transition KW - Socio-economic position Y1 - 2024 UR - https://www.sciencedirect.com/science/article/pii/S1569490924000042?via%3Dihub U6 - https://doi.org/10.1016/j.alcr.2024.100593 SN - 1879-6974 VL - Vol. 59 ER - TY - GEN A1 - Moor, Irene A1 - Winter, Kristina A1 - Bilz, Ludwig A1 - Bucksch, Jens A1 - Finne, Emily A1 - John, Nancy A1 - Kolip, Petra A1 - Paulsen, Lisa A1 - Ravens-Sieberer, Ulrike A1 - Schlattmann, Marina A1 - Sudeck, Gorden A1 - Brindley, Catherina A1 - Kaman, Anne A1 - Richter, Matthias T1 - Die Health Behaviour in School-aged Children (HBSC)-Studie 2017/18 – Methodik der Kinder- und Jugendgesundheits­studie der Weltgesundheitsorganisation T2 - Journal of Health Monitoring N2 - Die „Health Behaviour in School-Aged Children (HBSC)“-Studie ist ein international kooperatives Forschungsprojekt, das von der Weltgesundheitsorganisation (WHO) seit über 35 Jahren unterstützt wird. HBSC ist die weltweit größte Studie zur Kinder- und Jugendgesundheit und für die WHO eine der wichtigsten Datengrundlagen zur international vergleichenden Gesundheitsberichterstattung. Im vierjährigen Turnus werden Daten zur Gesundheit und zum Gesundheitsverhalten von Schülerinnen und Schülern im Alter von 11, 13 und 15 Jahren sowie zu den Rahmenbedingungen für ein gesundes Aufwachsen erhoben. Insgesamt gehören 50 Länder dem HBSC-Netzwerk an, an dem Survey 2017/18 beteiligten sich insgesamt 45 Länder. Deutschland beteiligt sich seit 1993/94 an der HBSC-Studie. Für die aktuelle Erhebung 2017/18 in Deutschland wurden Schülerinnen und Schüler an 146 Schulen befragt (Responserate Schulen: 15,6 %). Insgesamt konnte für Deutschland eine Netto-Stichprobe von n=4.347 Mädchen und Jungen (Responserate: 52,7 %) erzielt werden. Die freiwillige Teilnahme an der Befragung erfolgte in ganzen Schulklassen der Jahrgangsstufen fünf, sieben und neun. Mit Hilfe einer Gewichtung sind repräsentative Aussagen zur gesundheitlichen Lage von Kindern und Jugendlichen in Deutschland möglich. Die HBSC-Studie leistet einen wichtigen Beitrag für die Gesundheitsberichterstattung und bietet wichtige Ansatzpunkte für die Identifikation von Bedarfen, Risikogruppen und Handlungsfeldern, um gezielte und bedarfsorientierte Maßnahmen zur Prävention und Gesundheitsförderung im Setting Schule zu initiieren. Y1 - 2020 UR - https://www.rki.de/DE/Content/Gesundheitsmonitoring/Gesundheitsberichterstattung/GBEDownloadsJ/ConceptsMethods/JoHM_03_2020_HBSC_Methodik.pdf U6 - https://doi.org/10.25646/6896 SN - 2511-2708 VL - 5 IS - 3 SP - 93 EP - 108 ER - TY - GEN A1 - Haeberle, Jörg A1 - Richter, Matthias A1 - Galazka, Zbigniew A1 - Janowitz, Christoph A1 - Schmeißer, Dieter T1 - Resonant Photoemission at the O1s threshold to characterize In2O3 single crystals T2 - Thin Solid Films N2 - We report on spectroscopic investigations on In2O3 single crystals. We focus on the detailed analysis of the O1s resonance profile by resonant photoelectron spectroscopy. We analyze the electronic structure and assign the O2p to build the valence band and both, O2p and In5s5p states to contribute to the conduction band (CB). We determine the partial density of states for the valence and CBs and find a strong hybridization of O2p and In5s states. This is deduced from constant final state spectra on the O-KLL-Auger over the O K-edge and In M4,5-edge and a comparison to the corresponding X-ray absorption spectroscopy data.We also identify several types of defects. A broad band of oxygen derived defects is identified that extends throughout the gap. These are attributed to small polarons which cause an anti-resonance in the valence states around the O1s threshold. In addition, a separate Auger decay at resonance indicates the existence of localized charge transfer states which involves localized In5s5p states. KW - In2O3 KW - TCO KW - X-ray spectroscopy KW - Small polaron KW - Charge transfer Y1 - 2014 U6 - https://doi.org/10.1016/j.tsf.2013.03.036 SN - 0040-6090 SN - 1879-2731 VL - 2014 IS - 555 SP - 53 EP - 56 ER - TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Leszczynski, Sebastian A1 - Richter, Karola A1 - Knaut, Martin A1 - Reif, Johanna A1 - Völkel, Sandra A1 - Albert, Matthias A1 - Wenger, Christian A1 - Bartha, Johann Wolfgang A1 - Mikolajick, Thomas T1 - Improved Graphene-base Heterojunction Transistor with Different Collector Semi-conductors for High-frequency Applications T2 - Advanced Materials Letters N2 - A new kind of transistor device with a graphene monolayer embedded between two n-type silicon layers is fabricated and characterized. The device is called graphene-base heterojunction transistor (GBHT). The base-voltage controls the current of the device flowing from the emitter via graphene to the collector. The transit time for electrons passing by the ultrathin graphene layer is extremely short which makes the device very promising for high frequency RF-electronics. The output current of the device is saturated and clearly modulated by the base voltage. Further, the silicon collector of the GBHT is replaced by germanium to improve the device performance. This enabled the collector current to be increased by almost three orders of magnitude. Also, the common-emitter current gain (Ic/Ib) increased from 10-3 to approximately 0.3 for the newly designed device. However, the ON-OFF ratio of the improved germanium based GBHT has so far been rather low. Further optimizations are necessary in order to fully exploit the potential of the graphene-base heterojunction transistor. KW - Graphene KW - transistor Y1 - 2022 U6 - https://doi.org/10.5185/amlett.2022.011688 SN - 0976-3961 VL - 13 IS - 1 ER - TY - CHAP A1 - Rudolph, Matthias A1 - Dörner, Ralf A1 - Heymann, Peter A1 - Richter, E. T1 - Scaling of GaInP/GaAs HBT Equivalent-Circuit Elements Y1 - 1999 ER -