TY - JOUR A1 - Sabitova, A. A1 - Ebert, Ph. A1 - Lenz, A. A1 - Schaafhausen, S. A1 - Ivanova, L. A1 - Dähne, M. A1 - Hoffmann, A. A1 - Dunin-Borkowski, R. E. A1 - Förster, Arnold A1 - Grandidier, B. A1 - Eisele, H. T1 - Intrinsic bandgap of cleaved ZnO(112¯0) surfaces JF - Applied physics letters Y1 - 2013 SN - 1077-3118 (E-Journal); 0003-6951 (Print) VL - Vol. 102 SP - 021608 ER - TY - JOUR A1 - Bäcker, Matthias A1 - Raue, Markus A1 - Schusser, Sebastian A1 - Jeitner, C. A1 - Breuer, L. A1 - Wagner, P. A1 - Poghossian, Arshak A1 - Förster, Arnold A1 - Mang, Thomas A1 - Schöning, Michael Josef T1 - Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films JF - Physica Status Solidi (a) N2 - Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3–12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off. Y1 - 2012 U6 - http://dx.doi.org/10.1002/pssa.201100763 SN - 1862-6319 VL - 209 IS - 5 SP - 839 EP - 845 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Förster, Arnold A1 - Lepsa, M. I. A1 - Freundt, D. T1 - Hot electron injector Gunn diode for advanced driver assistance systems JF - Applied physics A: materials science and processing. 87 (2007), H. 3 Y1 - 2007 SN - 0947-8396 N1 - ISSN der E-Ausg.: 1432-0630 ; Special issue SP - 545 EP - 558 ER - TY - JOUR A1 - Förster, Arnold A1 - Mikulics, M. A1 - Wu, S. A1 - Marso, M. T1 - Ultrafast and Highly Sensitive Photodetectors With Recessed Electrodes Fabricated on Low-Temperature-Grown GaAs. Mikulics, M.; Wu, S.; Marso, M.; Adam, R.; Förster, A.; van der Hart, A.; Kordos, P.; Lüth, H.; Sobolewski, R. JF - IEEE Photonics Technology Letters. 18 (2006), H. 7 Y1 - 2006 SP - 820 EP - 822 ER - TY - CHAP A1 - Förster, Arnold A1 - Stock, Jürgen A1 - Montanari, Simone A1 - Lepsa, Mihail Ion A1 - Lüth, Hans T1 - Fabrication and characterisation of GaAs Gunn Diode Chips for applications at 77 GHz in automotive industry N2 - GaAs-based Gunn diodes with graded AlGaAs hot electron injector heterostructures have been developed under the special needs in automotive applications. The fabrication of the Gunn diode chips was based on total substrate removal and processing of integrated Au heat sinks. Especially, the thermal and RF behavior of the diodes have been analyzed by DC, impedance and S-parameter measurements. The electrical investigations have revealed the functionality of the hot electron injector. An optimized layer structure could fulfill the requirements in adaptive cruise control (ACC) systems at 77 GHz with typical output power between 50 and 90 mW. KW - Biosensor KW - Gunn diode KW - microwave generation KW - GaAs hot electron injector Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1462 ER - TY - JOUR A1 - Förster, Arnold A1 - Montanari, Simone A1 - Lepsa, Mihail Ion A1 - Lüth, Hans T1 - High frequency investigation of graded gap injectors for GaAs Gunn diodes / Simone Montanari ; Arnold Förster ; Mihail Ion Lepsa ; Hans Lüth JF - Solid-state electronics. 49 (2005), H. 2 Y1 - 2005 SN - 0038-1101 SP - 245 EP - 250 ER - TY - JOUR A1 - Mikulics, M. A1 - Marso, M. A1 - Cámara Mayorga, I. A1 - Gusten, R. A1 - Stancek, S. A1 - Michael, E. A. A1 - Schieder, R. A1 - Wolter, M. A1 - Buca, D. A1 - Förster, Arnold A1 - Kordos, P. A1 - Lüth, H. T1 - Photomixers fabricated on nitrogen-ion-implanted GaAs JF - Applied physics letters. 87 (2005) Y1 - 2005 SP - 041106-1 EP - 041106-3 ER - TY - JOUR A1 - Förster, Arnold A1 - Marso, M. A1 - Mikulics, V. V. A1 - Adam, R. T1 - Ultrafast Phenomena in Freestanding LT-GaAs Devices. Marso, M.; Mikulics, V. V.; Adam, R.; Wu, S.; Zheng, X.; Camara, I.; Siebe, N. Y.; Förster, A.; Güsten, R.; Kordos, P.; Sobolewski, R. JF - Acta physica Polonica / A. 107 (2005), H. 1 Y1 - 2005 SN - 0587-4246 SP - 109 EP - 117 ER - TY - JOUR A1 - Förster, Arnold A1 - Wensorra, J. A1 - Indlekofer, K. M. A1 - Lüth, H. T1 - Resonant tunneling in nanocolumns improved by quantum collimation. Wensorra, J.; Indlekofer, K. M.; Förster, A.; Lüth, H. JF - Nano Letters. 5 (2005) Y1 - 2005 SN - 0587-4246 SP - 2470 EP - 2475 ER - TY - JOUR A1 - Mikulics, M. A1 - Adam, R. A1 - Kordos, P. A1 - Förster, Arnold A1 - Lüth, H. A1 - Wu, S. A1 - Zheng, X. A1 - Sobolewski, R. T1 - Ultrafast low-temperature-grown epitaxial GaAs photodetectors transferred on flexible plastic substrates JF - IEEE photonics technology letters : IEEE PTL. 17 (2005), H. 8 Y1 - 2005 SN - 1041-1135 SP - 1725 EP - 1727 ER -