TY - JOUR A1 - Berndt, Dominik A1 - Muggli, Josef A1 - Heckel, Robert A1 - Rahiman, Mohd Fuad A1 - Lindner, Matthias A1 - Heinrich, Stephan A1 - Plöchinger, Heinz A1 - Schreiner, Rupert T1 - A Robust Miniaturized Gas Sensor for H₂ and CO₂ Detection Based on the 3ω Method JF - Sensors N2 - Gas concentration monitoring is essential in industrial or life science areas in order to address safety-relevant or process-related questions. Many of the sensors used in this context are based on the principle of thermal conductivity. The 3ω-method is a very accurate method to determine the thermal properties of materials. It has its origin in the thermal characterization of thin solid films. To date, there have been very few scientific investigations using this method to determine the thermal properties of gases and to apply it to gas measurement technology. In this article, we use two exemplary gases (H2 and CO2) for a systematical investigation of this method in the context of gas analysis. To perform our experiments, we use a robust, reliable sensing element that is already well established in vacuum measurement technology. This helix-shaped thin wire of tungsten exhibits high robustness against chemical and mechanical influences. Our setup features a compact measurement environment, where sensor operation and data acquisition are integrated into a single device. The experimental results show a good agreement with a simplified analytical model and FEM simulations. The sensor exhibits a lower detection limit of 0.62% in the case of CO2, and only 0.062% in case the of H2 at an excitation frequency of 1 Hz. This is one of the lowest values reported in literature for thermal conductivity H2 sensors. KW - 3ω-method KW - CO2 sensor KW - H2 sensor KW - thermal gas sensor Y1 - 2022 U6 - https://doi.org/10.3390/s22020485 N1 - Corresponding author: Dominik J. Berndt VL - 22 IS - 2 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schreiner, Rupert A1 - Körbl, M. A1 - Gräbeldinger, H. A1 - Gentner, Jean-Louis A1 - Schweizer, H. T1 - Laterally gain-coupled 1.57 [micro sign]m DFB lasers with chromium surface grating and self-aligned Ti/Pt/Au ohmic contact JF - Electronics Letters N2 - A simple method for fabricating gain coupled DFB lasers with lateral surface chromium Bragg gratings and self-aligned low capacitance ohmic contacts is reported. These InGaAsP/InP lasers show monomode emission with a sidemode suppression ratio of 40 dB. For 243 µm long devices a continuous wave threshold current of 17 mA was measured at room temperature. KW - Bragg gratings KW - platinum KW - chromium KW - ohmic contacts KW - titanium KW - distributed feedback lasers KW - gold Y1 - 2000 U6 - https://doi.org/10.1049/el:20000500 SN - 0013-5194 VL - 36 IS - 7 SP - 636 EP - 637 PB - The Institution of Engineering and Technology, IET ER - TY - JOUR A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Dams, Florian T1 - Compact and Energy-Efficient Field Emission Cathodes for Sensor Applications JF - Advanced Materials Research N2 - We report on miniaturized silicon field emitter arrays for the application in compact and energy-saving vacuum-microelectronic devices, e.g. sensors or x-ray tubes. Since standard silicon semiconductor technology has been used for the fabrication, they may be easily integrated with other silicon based circuits and devices on the same chip. The silicon tip geometry and the operating conditions were optimized in order to obtain highly uniform and stable electron field emission from large area cathode arrays. A series of uniform hexagonal tip arrays containing each 547 tips were fabricated and characterized. The electron emission properties of both individual tips as well as of complete emitter arrays were investigated. A saturation level in the voltage-current characteristics was found, which can be explained by the limitation of the supply of electrons due to the p-type silicon wafer material. When operating the arrays in the current saturation regime at an emission current of ~ 1 nA per tip, a highly stable and low noise emission can be observed. KW - field emission KW - Si-Tip Cathodes KW - Vacuum Sensors Y1 - 2014 U6 - https://doi.org/10.4028/www.scientific.net/amr.1024.372 VL - 1024 SP - 372 EP - 375 PB - Scientific.net ER - TY - CHAP A1 - Hausladen, Matthias A1 - Bomke, Vitali A1 - Buchner, Philipp A1 - Bachmann, Michael A1 - Knapek, Alexandr A1 - Schreiner, Rupert T1 - Influence of Geometrical Arrangements of Si Tip Arrays Fabricated by Laser Micromachining on their Emission Behaviour T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - ensely packed emitters on a field emission array lead typically to mutual shielding. Taking biology as a role model for geometric arrangements could be a way to reduce this effect. For comparison, two electron sources, one with a spiral and a second with conventional rectangular (orthogonal) arranged emitters, were fabricated and investigated. Emission currents of 6 µA in the spiral ordered array and 120 µA in the rectangular array were reached with an extraction voltage of 400 V. From a mid-term measurement over 1 h a current stability of ±8.8 % (spiral) respectively ±5.7 % (rectangular) with a mean degradation of -3.0 µA/h (spiral) and -0.12 µA/h (rectangular) could be observed. KW - aperture field KW - emission grid KW - Fabrication KW - laser micromachining KW - parastichy tip arrangements KW - silicon field emission KW - Stability analysis KW - Spirals KW - Field emitter array KW - Voltage measurement Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600717 SN - 2380-6311 PB - IEEE CY - Piscataway, N.J. ER - TY - CHAP A1 - Buchner, Philipp A1 - Bomke, Vitali A1 - Hausladen, Matthias A1 - Edler, Simon A1 - Bachmann, Michael A1 - Schreiner, Rupert T1 - Investigation on the Emission Behaviour of p-doped Silicon Field Emission Arrays with Individually Controllable Single Tips T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 7/5/2021 - 7/9/2021, Lyon, France N2 - Four individually controllable emission tips consisting of <111> p-Type silicon, were structured on a glass substrate by laser ablation. A matching extraction grid was manufactured in the same manner and aligned with the emitters. The resulting samples were characterized in ultra-high vacuum. As expected, the individual currents show a strong saturation and in the saturation region a considerably lower current fluctuation than n-type silicon due to charge carrier depletion. The individual tips behave completely independent behaviour from each other and the overall emission can be deduced from the sum of the currents through the individual tips. Y1 - 2021 SN - 978-1-6654-2589-6 U6 - https://doi.org/10.1109/IVNC52431.2021.9600756 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Hecht, Fabian A1 - Bauereiβ, Florian A1 - Sellmair, Josef A1 - Buchner, Philipp A1 - Hausladen, Matthias A1 - Schreiner, Rupert T1 - Electron Beam Induced Growth of Carbon Nanotips on Tungsten and Silicon Fieldemitters T2 - 2023 IEEE 36th International Vacuum Nanoelectronics Conference (IVNC), 10-13 July 2023, Cambridge, MA, USA N2 - In our experiments we grew electron emitting carbon nanostructures on tungsten tips. Subsequently, we transferred the growth process to pre-structured phosphorus-doped n-type silicon and obtained emitting carbon nanostructures directly grown on silicon. After growth of the nanostructures, the silicon field emitters showed increased emission currents of 76 nA at 1.1 kV (compared to 6 nA under the same conditions before growth). KW - Behavioral sciences KW - Nanostructures KW - Silicon KW - Carbon dioxide KW - Current measurement KW - Electron beams KW - Tungsten Y1 - 2023 SN - 979-8-3503-0143-4 U6 - https://doi.org/10.1109/IVNC57695.2023.10188960 SP - 160 EP - 162 PB - IEEE ER - TY - CHAP A1 - Allaham, Mohammad M. A1 - Buchner, Philipp A1 - Schreiner, Rupert A1 - Knápek, Alexandr T1 - Testing the performance of Murphy-Good plots when applied to current-voltage characteristics of Si field electron emission tips T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France N2 - Murphy-Good plots are the most recent type of the analysis methods in the field electron emission theory, this type of plots has several useful characteristics such as: having the very-nearly straight line to represent the current-voltage characteristics and the absence of the correction factors in the mathematical procedure of the analysis process. In this study, n-type <111> and <100> Si chips containing four individual emitters are used as base emitters and mounted in a diode configuration field emission setup where the experiments are operated in an ultra-high vacuum ( 10-7 Pa). Each chip has four individual controllable emitters with 5 µm distance between the Si tips and the same material grid. Laser micromachining and subsequent wet chemical etching technique is used to structure and polish the tips. Murphy-Good plots are used to study the behavior of the Si individual tips and compare the results with the array current by extracting the field emission characterization parameters of the emitters. KW - characterization parameter KW - Current-voltage characteristics KW - electron emission KW - electron source KW - Limiting KW - Micromachining KW - Murphy-Good plot KW - n-type Si chip KW - RESISTANCE KW - safety KW - silicon Y1 - 2021 U6 - https://doi.org/10.1109/IVNC52431.2021.9600690 SP - 1 EP - 2 PB - IEEE ER - TY - CHAP A1 - Zheng, Jihong A1 - Fuhrmann, Thomas A1 - Xu, Boqing A1 - Schreiner, Rupert A1 - Jia, Hongzhi A1 - Zhang, Wei A1 - Wang, Ning A1 - Seebauer, Gudrun A1 - Zhu, Jiyan T1 - Curriculum design and German student exchange for Sino-German Bachelor program majored in optoelectronics engineering T2 - 14th Conference on Education and Training in Optics and Photonics (ETOP 2017), 29-31.05.2017, Hangzhou, China, 29-31.05.2017 N2 - 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. KW - cooperative bachelor program KW - optoelectronics KW - microsystems KW - student exchange Y1 - 2017 U6 - https://doi.org/10.1117/12.2269574 PB - SPIE ER - TY - CHAP A1 - Bieker, Johannes A1 - Roustaie, Farough A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Schlaak, Helmut F. T1 - Innovatives Verfahren zur Herstellung und Integration metallischer Nanokonen für die Feldemission T2 - MikroSystemTechnik Kongress 2017 : MEMS, Mikroelektronik, Systeme 23.-25. Oktober 2017 in München N2 - In den letzten Jahren wurde am Institut für Elektromechanische Konstruktionen die Fabrikation und Integration von metallischen Nanodrähten und Nanokonen mittels Template-basierter Abscheidung erforscht. Diese Variante der in-situ Abscheidung von metallischen Nanostrukturen bietet eine Vielzahl von Anwendungsmöglichkeiten. Im Rahmen dieses Beitrags werden das Herstellungsverfahren zur Herstellung metallischer Nanokonen vorgestellt. Dies beinhaltet sowohl die Templatepräparation mittels asymmetrischen Ätzens 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 Langzeitstabilität des Feldemissionsstromes der metallischen Konen präsentiert. N2 - Recently the fabrication and integration of metallic nanowires and nanocones based on ion-track etched templates has been in the focus of research at the Institute for Electromechanical Design at the TU Darmstadt. Using the method for the in-situ deposition various applications are feasible. In this paper we present the fabrication method for in-situ deposition of metallic nanocones, including the preparation of the polymer templates based on asymmetric etching and the process description for integration via electrodeposition. Giving one example for an application, the metallic nanocones can be used as field emitters in vacuum electronics. The field emission properties will be presented briefly. T2 - Innovative fabrication method for in-situ deposition of metallic nanocones for field emission KW - Ätzen KW - Feldemission KW - galvanische Abscheidung KW - Herstellverfahren KW - Langzeitstabilität KW - Nanodraht KW - Nanostruktur KW - Polymer KW - Prozessbeschreibung KW - Vakuum Y1 - 2017 SN - 978-3-8007-4491-6 IS - CD-ROM SP - 797 EP - 800 PB - VDE-Verlag CY - München ER - TY - CHAP A1 - Rahiman, Mohd Fuad A1 - Berndt, Dominik A1 - Schreiner, Rupert T1 - Micro-wire Pirani with temperature-stabilized Environment T2 - 3. Symposium Elektronik und Systemintegration ESI 2022: 06. April 2022, Hochschule Landshut Y1 - 2022 SN - 978-3-9818439-7-2 SP - 52 EP - 59 ER - TY - GEN A1 - Schreiner, Rupert T1 - Miniaturized sensor and actuator elements based on the heat transport in gases or the ionization of gas particles T2 - 16th International Conference on Optical and Electronic Sensors, COE'2020, 29 March - 2 April 2020, Krakow, Poland (online) Y1 - 2021 ER - TY - CHAP A1 - Kleshch, Victor I. A1 - Serbun, Pavel A1 - Orekhov, Anton A1 - Lützenkirchen-Hecht, Dirk A1 - Obraztsov, Alexander N. A1 - Prommesberger, Christian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Lutzenkirchen-Hecht, Dirk T1 - Field emission properties of p-type silicon tips decorated with tungsten nanoparticles T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - 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. KW - Current measurement KW - field emission KW - Ions KW - Iron KW - metal nanoparticles KW - nanoparticles KW - p-type silicon KW - Scanning electron microscopy KW - silicon KW - Tungsten Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051580 SP - 138 EP - 139 PB - IEEE ER - TY - CHAP A1 - Wick, Michael A1 - Lindner, Gerhard A1 - Zimmer, Katja A1 - Schreiner, Rupert A1 - Fuhrmann, Thomas A1 - Seebauer, Gudrun A1 - Xu, Boqing A1 - Zheng, Jihong A1 - Wang, Ning ED - Liu, Xu ED - Zhang, Xi-Cheng T1 - German-Chinese cooperative Bachelor in engineering physics/optoelectronics T2 - 14th Conference on Education and Training in Optics and Photonics: ETOP 2017; Hangzhou, China 29.05.2017 - 31.05.2017 N2 - 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. Y1 - 2017 SN - 9781510613812 U6 - https://doi.org/10.1117/12.2269943 PB - SPIE ER -