@inproceedings{ZhengFuhrmannXuetal., author = {Zheng, Jihong and Fuhrmann, Thomas and Xu, Boqing and Schreiner, Rupert and Jia, Hongzhi and Zhang, Wei and Wang, Ning and Seebauer, Gudrun and Zhu, Jiyan}, title = {Curriculum design and German student exchange for Sino-German Bachelor program majored in optoelectronics engineering}, series = {14th Conference on Education and Training in Optics and Photonics (ETOP 2017), 29-31.05.2017, Hangzhou, China, 29-31.05.2017}, booktitle = {14th Conference on Education and Training in Optics and Photonics (ETOP 2017), 29-31.05.2017, Hangzhou, China, 29-31.05.2017}, publisher = {SPIE}, doi = {10.1117/12.2269574}, pages = {134}, abstract = {Different higher education backgrounds in China and Germany led to challenges in the curriculum design at the beginning of our cooperative bachelor program in Optoelectronics Engineering. We see challenges in different subject requirements from both sides and in the German language requirements for Chinese students. The curriculum was optimized according to the AS IIN criteria, which makes it acceptable and und erstandable by both countries. German students are integrated into the Chinese class and get the sa me lectures like their Chinese colleagues. Intercultural and curriculum challenges are successfully solved. The results are summarized to provide an example for other similar international programs.}, language = {en} } @inproceedings{BiekerRoustaieLangeretal., author = {Bieker, Johannes and Roustaie, Farough and Langer, Christoph and Schreiner, Rupert and Schlaak, Helmut F.}, title = {Innovatives Verfahren zur Herstellung und Integration metallischer Nanokonen f{\"u}r die Feldemission}, series = {MikroSystemTechnik Kongress 2017 : MEMS, Mikroelektronik, Systeme 23.-25. Oktober 2017 in M{\"u}nchen}, booktitle = {MikroSystemTechnik Kongress 2017 : MEMS, Mikroelektronik, Systeme 23.-25. Oktober 2017 in M{\"u}nchen}, number = {CD-ROM}, publisher = {VDE-Verlag}, address = {M{\"u}nchen}, isbn = {978-3-8007-4491-6}, pages = {797 -- 800}, abstract = {In den letzten Jahren wurde am Institut f{\"u}r Elektromechanische Konstruktionen die Fabrikation und Integration von metallischen Nanodr{\"a}hten und Nanokonen mittels Template-basierter Abscheidung erforscht. Diese Variante der in-situ Abscheidung von metallischen Nanostrukturen bietet eine Vielzahl von Anwendungsm{\"o}glichkeiten. Im Rahmen dieses Beitrags werden das Herstellungsverfahren zur Herstellung metallischer Nanokonen vorgestellt. Dies beinhaltet sowohl die Templatepr{\"a}paration mittels asymmetrischen {\"A}tzens als auch die anschließende Integration mittels galvanischer Abscheidung. Eine Anwendung der metallischen Nanokonen stellt die Verwendung als Feldemitter in der Vakuumelektronik dar. Es werden erste Messungen der Langzeitstabilit{\"a}t des Feldemissionsstromes der metallischen Konen pr{\"a}sentiert.}, language = {de} } @inproceedings{KleshchSerbunOrekhovetal., author = {Kleshch, Victor I. and Serbun, Pavel and Orekhov, Anton and L{\"u}tzenkirchen-Hecht, Dirk and Obraztsov, Alexander N. and Prommesberger, Christian and Langer, Christoph and Schreiner, Rupert and Lutzenkirchen-Hecht, Dirk}, title = {Field emission properties of p-type silicon tips decorated with tungsten nanoparticles}, series = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, booktitle = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051580}, pages = {138 -- 139}, abstract = {An array of conical-shaped p-type silicon tips was fabricated by using reactive ion etching and sharpening oxidation. The apex of each tip was decorated by a tungsten hemispherical nanoparticle. Field emission properties of the tips were measured by a tungsten-needle anode positioned above the tip apex. Tips decorated with tungsten nanoparticles demonstrated a smaller saturation region in current-voltage characteristics compared to the pristine tips. An emission activation process, which consisted in sudden current increase at certain value of applied voltage, was observed for the decorated silicon tips. This behavior was explained by the formation of vertical protrusions extending from the metal particles revealed by scanning electron microscopy after field emission experiments.}, language = {en} } @inproceedings{WickLindnerZimmeretal., author = {Wick, Michael and Lindner, Gerhard and Zimmer, Katja and Schreiner, Rupert and Fuhrmann, Thomas and Seebauer, Gudrun and Xu, Boqing and Zheng, Jihong and Wang, Ning}, title = {German-Chinese cooperative Bachelor in engineering physics/optoelectronics}, series = {14th Conference on Education and Training in Optics and Photonics: ETOP 2017; Hangzhou, China 29.05.2017 - 31.05.2017}, booktitle = {14th Conference on Education and Training in Optics and Photonics: ETOP 2017; Hangzhou, China 29.05.2017 - 31.05.2017}, editor = {Liu, Xu and Zhang, Xi-Cheng}, publisher = {SPIE}, isbn = {9781510613812}, doi = {10.1117/12.2269943}, abstract = {The University of Shanghai for Science and Technology (USST), the Coburg University of Applied Sciences and Arts (CUASA) and the OTH Regensburg, University of Applied Sciences (OTHR) established an English taught international cooperative bachelor program in the area of Engineering Physics/Optoelectronics. Students from China study their first four semesters at USST. They continue their studies in Germany for the last three semesters, including an internship and a bachelor thesis, graduating with a Chinese and a German bachelor degree. Students from Germany study their third and fourth semester at USST to gain international experience. While the first cohort of Chinese students is currently in Germany, the second cohort of German students is in Shanghai. Up to now the feedback regarding this study program is completely positive, thus it is planned to develop it further.}, language = {en} } @inproceedings{KnappLangerPrommesbergeretal., author = {Knapp, Wolfram and Langer, Christoph and Prommesberger, Christian and Lindner, Matthias and Schreiner, Rupert}, title = {Investigations of the transition from field electron emission to stable plasma discharge in a micro electron source at vacuum pressure}, series = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, booktitle = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051594}, pages = {166 -- 167}, abstract = {We report on the transition from field electron emission to plasma discharges. During an experiment with a miniaturized field emission electron source a plasma discharge accompanied by a luminous effect was observed. A novel graphical evaluation method was used to interpret and to compare the observed phenomenon.}, language = {en} } @article{PrommesbergerBachmannDuesbergetal., author = {Prommesberger, Christian and Bachmann, Michael and D{\"u}sberg, Felix and Langer, Christoph and Ławrowski, Robert Damian and Hofmann, Martin and Pahlke, Andreas and Schreiner, Rupert}, title = {Regulation of the Transmitted Electron Flux in a Field-Emission Electron Source Demonstrated on Si Nanowhisker Cathodes}, series = {IEEE Transactions on Electron Devices}, volume = {64}, journal = {IEEE Transactions on Electron Devices}, number = {12}, publisher = {IEEE}, issn = {5128-5133}, doi = {10.1109/TED.2017.2763239}, abstract = {We report on a method to stabilize the transmitted electron flux in a field-emission electron source using an external regulation circuit. The electron source was realized with an array of silicon (Si) nanowhiskers on the top of elongated pillar structures, a mica spacer, and an extraction grid made of Si. As for most applications, the emitted electron current from the cathode is not as crucial as the transmitted electron flux through the extraction grid toward the anode. We investigated a method which allows the regulation directly by the emitted electron flux and not merely on the cathode current. By using this method, we were able to stabilize the emitted electron flux of our electron source down to values below 1\%. Simultaneously, it was shown that there is the possibility to stabilize the influencing value in the real application as well. The effectiveness of this method was demonstrated successfully with an X-ray source setup. The measured X-ray photon count rate was stabilized to a standard deviation of 0.30\% at a pressure of 1 × 10 -7 mbar. Even in harsh environment of 2 × 10 -5 mbar, a stabilization of the X-ray photon count rate down to a value of 0.63\% was achieved.}, language = {en} } @article{EdlerBachmannBreueretal., author = {Edler, Simon and Bachmann, Michael and Breuer, Janis and Dams, Florian and D{\"u}sberg, Felix and Hofmann, Martin and Jakšič, Jasna and Pahlke, Andreas and Langer, Christoph and Ławrowski, Robert Damian and Prommesberger, Christian and Schreiner, Rupert}, title = {Influence of adsorbates on the performance of a field emitter array in a high voltage triode setup}, series = {Journal of Applied Physics}, volume = {122}, journal = {Journal of Applied Physics}, doi = {10.1063/1.4987134}, abstract = {In the present work, black-silicon field emitter arrays (FEAs) are investigated regarding the influence of residual gas pressure on the characteristics and lifetime in the high voltage triode setup. Current-voltage-characteristics at different pressure levels are recorded and show a decreasing emission current with rising pressure. This decrease can be explained by an increase of the work function and charging of the emitter surface caused by adsorbates. The emission current can be restored to its initial value by heating of the FEA up to 110 °C during active emission. With this regeneration procedure, an extended lifetime from about 20 h to 440 h at a residual gas pressure of 10-5 mbar is achieved.}, language = {en} } @article{BachmannDamsDuesbergetal., author = {Bachmann, Michael and Dams, Florian and D{\"u}sberg, Felix and Hofmann, Martin and Pahlke, Andreas and Langer, Christoph and Ławrowski, Robert Damian and Prommesberger, Christian and Schreiner, Rupert and Serbun, Pavel and L{\"u}tzenkirchen-Hecht, Dirk and M{\"u}ller, G{\"u}nter}, title = {Extraction of the characteristics of current-limiting elements from field emission measurement data}, series = {Journal of Vacuum Science \& Technology B}, volume = {35}, journal = {Journal of Vacuum Science \& Technology B}, number = {2}, doi = {10.1116/1.4971768}, abstract = {In this contribution, the authors will present an algorithm to extract the characteristics of nonideal field emission circuit elements from saturation-limited field emission measurement data. The method for calculating the voltage drop on current-limiting circuit elements is based on circuit theory as well as Newton's method. Since the only assumption the authors make on the current-limiting circuit is a connection in series, this method is applicable to most field emission data showing saturation. To be able to determine the significance of any parameter output, the uncertainties of data and extracted parameters as well as the parameter correlations are fully taken into account throughout the algorithm. N-type silicon samples with varying external serial resistors are analyzed. All results show a good agreement to the nominal resistor values. Additionally, several p-type samples are analyzed, showing a diodelike behavior. The extracted current-limiting characteristics of the p-type samples are in good agreement with a pn-junction model. The stability of the emission current of the p-type samples is measured by constant voltage measurements and compared to the extracted current-limiting characteristics. The application of the algorithm to measurement data shows that the given algorithm is a valuable tool to analyze field emission measurement data influenced by nonemissive processes.}, language = {en} } @article{PrommesbergerLangerŁawrowskietal., author = {Prommesberger, Christian and Langer, Christoph and Ławrowski, Robert Damian and Schreiner, Rupert}, title = {Investigations on the long-term performance of gated p-type silicon tip arrays with reproducible and stable field emission behavior}, series = {Journal of Vacuum Science \& Technology B}, volume = {35}, journal = {Journal of Vacuum Science \& Technology B}, number = {1}, doi = {10.1116/1.4972519}, abstract = {The authors report on the fabrication and characterization of p-type Si tip arrays with an integrated gate electrode for applications as field emission electron sources. After the reactive ion etching of the emitters, the combined thermal dry and wet oxidation was used for both the sharpening of the emitters and for the realization of an enhanced insulation layer. Au was evaporated in a self-aligned process as gate electrode. Arrays of 16 Si tips were fabricated with tip heights of about 3 μm and tip radii of about 20 nm with integrated gate electrode concentrically positioned ≈2 μm below the tip apex. Integral measurements with an additional anode showed improved field emission properties with a reproducible and stable emission behavior. A fast activation of the tips, low onset voltages of about 30 V, and moderate field emission currents up to 0.55 μA were noticed. The field emission parameters were calculated using the Fowler-Nordheim characteristics. A pronounced saturation regime was observed, and current fluctuations of less than ±1\% were investigated for 30 min. Long-term measurements were carried out for a period of more than 8 h. In the first 6 h of operation, the authors observed a drift of the emission current from 0.35 to 0.55 μA caused by an increased emission surface.}, language = {en} } @inproceedings{PrommesbergerŁawrowskiLangeretal., author = {Prommesberger, Christian and Ławrowski, Robert Damian and Langer, Christoph and Mecani, Mirgen and Huang, Yifeng and She, Juncong and Schreiner, Rupert}, title = {Field emission properties of ring-shaped Si ridges with DLC coating}, series = {Proc. SPIE 10248, Nanotechnology VIII, 102480H (30 May 2017)}, volume = {102480H}, booktitle = {Proc. SPIE 10248, Nanotechnology VIII, 102480H (30 May 2017)}, editor = {Tiginyanu (Ed.), Ion M.}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, doi = {10.1117/12.2265627}, abstract = {We report on the fabrication and the emission characterization of single ring-shaped Si ridges with a coating of diamond-like carbon (DLC). The reactive ion etching and the subsequent inductively coupled plasma step were adjusted to realize ring-shaped Si ridges with a height of 7.5 μm respectively 15 μm and an apex radius of 20 - 25 nm. The samples were coated with a DLC layer (thickness ≈ 2 - 5 nm) by a filtered cathodic vacuum arc deposition system in order to lower the work function of the emitter and to improve the field emission characteristics. The field emission characterizations were done in diode configuration with cathode and anode separated by a 50 μm thick mica spacer. A higher emission current was carried out for the ring-shaped Si ridge in comparison to the point-shaped Si tips due to the increased emission area. The highest emission current of 0.22 μA at 1000 V was measured on a DLC-coated sample with the highest aspect ratio. No degradation of the emission current was observed in the plateau regime during a measurement period of 6 h. Finally, no decreasing performance of the field emission properties was found due to changes in the geometry or destructions.}, language = {en} } @inproceedings{ŁawrowskiLangerPrommesbergeretal., author = {Ławrowski, Robert Damian and Langer, Christoph and Prommesberger, Christian and Schreiner, Rupert}, title = {Microrods and microlines by three-dimensional epitaxially grown GaN for field emission cathodes}, series = {International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051576}, pages = {130 -- 131}, abstract = {The three-dimensional epitaxial technique allows the realization of gallium nitride lines in addition to the rods. To optimize the properties of GaN-based field emission cathodes further investigations and an improvement of the epitaxial process were performed. The microrods and microlines consist of a one-order higher n-doped gallium nitride in comparison to the gallium nitride layer on the sapphire substrate. The typical height of the microrods and -lines is about 5 μm. The field emission properties of these structures were investigated in diode configuration by integral field emission measurements at pressures below 10 -9 mbar. For the microrods (microlines) a voltage of 1100 V (2000 V) was measured for a field emission current of about 0.5 μA with an onset field of about 12 MV/m (24 MV/m). Furthermore, the field enhancement factors for microrods and -lines are in the range of 300 and 200, respectively.}, language = {en} } @inproceedings{BachmannDamsDuesbergetal., author = {Bachmann, Michael and Dams, Florian and D{\"u}sberg, Felix and Hofmann, Martin and Pahlke, Andreas and Langer, Christoph and Ławrowski, Robert Damian and Prommesberger, Christian and Schreiner, Rupert}, title = {Control of the electron source current}, series = {International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051550}, pages = {66 -- 67}, abstract = {A control circuit to stabilize the flux of electrons transmitted through an extractor electrode is presented. By controlling the emission current a fluctuation with a standard deviation of 0.015\% is observed. However, the achievable stability of the transmitted electron current is limited due to a variation of the extraction grid current ratio showing a standard deviation of 4.33\%. By regulating the difference of the emission current and the extraction grid current an improved stability of the transmitted electron current down to a standard deviation of 0.280\% is observed. Even with operation at 2 × 10 -5 mbar a standard deviation of 0.558\% is achieved.}, language = {en} } @inproceedings{PrommesbergerLangerŁawrowskietal., author = {Prommesberger, Christian and Langer, Christoph and Ławrowski, Robert Damian and Schreiner, Rupert}, title = {Benzocyclobutene as a novel integrated spacer material in a field emission electron source}, series = {International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg}, booktitle = {International Vacuum Nanoelectronics Conference (IVNC), 30th, 2017, Regensburg}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051605}, pages = {192 -- 193}, abstract = {For the realization of a miniaturized field emission electron source we tested benzocyclobutene (BCB) as a new spacer material between cathode and anode. We fabricated black silicon emitters and characterized the emission behavior with an integrated 5 μm thin and large-area spacer of BCB. The integrated BCB layer allows the realization of a compact electron source with only two components consisting of a cathode with BCB and a grid. The comparison with other spacer materials like polyimide (25 μm thickness) or mica (50 μm thickness) revealed for the cathode with BCB a significantly reduced operational voltage of 240 V for a field emission current of 1 μA.}, language = {en} } @inproceedings{ŁawrowskiLangerPrommesbergeretal., author = {Ławrowski, Robert Damian and Langer, Christoph and Prommesberger, Christian and Schreiner, Rupert}, title = {Light emitting diodes based on three-dimensional epitaxial grown crystalline GaN rods}, series = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, booktitle = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, publisher = {VDE-Verlag}, address = {M{\"u}nchen}, isbn = {978-3-8007-4491-6}, pages = {131 -- 134}, language = {en} } @misc{WeberDendorferSuessetal., author = {Weber, Karsten and Dendorfer, Sebastian and S{\"u}ß, Franz and Kubowitsch, Simone and Schratzenstaller, Thomas and Haug, Sonja and Mohr, Christa and Kiesl, Hans and Drechsler, J{\"o}rg and Westner, Markus and Kobus, J{\"o}rn and Schubert, Martin J. W. and Zenger, Stefan and Pietsch, Alexander and Weiß, Josef and Hinterseer, Sebastian and Schieck, Roland and Scherzinger, Stefanie and Klettke, Meike and Ringlstetter, Andreas and St{\"o}rl, Uta and Bissyand{\´e}, Tegawend{\´e} F. and Seeburger, Achim and Schindler, Timo and Ramsauer, Ralf and Kiszka, Jan and K{\"o}lbl, Andreas and Lohmann, Daniel and Mauerer, Wolfgang and Maier, Johannes and Scorna, Ulrike and Palm, Christoph and Soska, Alexander and Mottok, J{\"u}rgen and Ellermeier, Andreas and V{\"o}gele, Daniel and Hierl, Stefan and Briem, Ulrich and Buschmann, Knut and Ehrlich, Ingo and Pongratz, Christian and Pielmeier, Benjamin and Tyroller, Quirin and Monkman, Gareth J. and Gut, Franz and Roth, Carina and Hausler, Peter and Bierl, Rudolf and Prommesberger, Christian and Ławrowski, Robert Damian and Langer, Christoph and Schreiner, Rupert and Huang, Yifeng and She, Juncong and Ottl, Andreas and Rieger, Walter and Kraml, Agnes and Poxleitner, Thomas and Hofer, Simon and Heisterkamp, Benjamin and Lerch, Maximilian and Sammer, Nike and Golde, Olivia and Wellnitz, Felix and Schmid, Sandra and Muntschick, Claudia and Kusterle, Wolfgang and Paric, Ivan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Schmidt, Ottfried and Schwanzer, Peter and Rabl, Hans-Peter and Sterner, Michael and Bauer, Franz and Steinmann, Sven and Eckert, Fabian and Hofrichter, Andreas}, title = {Forschungsbericht 2017}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-3-5}, doi = {10.35096/othr/pub-1383}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13835}, subject = {Forschung}, language = {de} } @inproceedings{BiekerRoustaieSchlaaketal., author = {Bieker, Johannes and Roustaie, Farough and Schlaak, Helmut F. and Langer, Christoph and Schreiner, Rupert}, title = {Field emission characterization of in-situ deposited metallic nanocones}, series = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, booktitle = {2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany}, publisher = {IEEE}, doi = {10.1109/IVNC.2017.8051571}, pages = {120 -- 121}, abstract = {An in-situ fabrication technique based on ion track etched template electrodeposition of metallic nanocones was used for the production of field emitter cathodes. Gold nanocones with a height of 24 microns, a base diameter between 3 to 4 microns and a tip diameter below 300 nanometers were deposited on a circular electrode with a diameter of 2.5 mm. The integral field emission (FE) measurements of samples with cone densities of 6 · 104 cones/cm2 (sample A) and 1 · 106 cones/cm2 (sample B) yielded in a maximum current of 37.5 μA at an applied field of 12.5 V/μm for sample A and 29.1 μA at 9.4 V/μm for sample B. The stability of emission current was investigated for over 48 hours and no degradation was observed.}, language = {en} }