SG01D-5Lens

Dr. Tilman Weiss, sglux GmbH, Berlin, Germany
Yuyu Kimura, IR System Co., Ltd., Tokyo, Japan

This article was first published in the Japanese Journal of Industrial Heating 2025, vol. 62, no. 3, Edition May

Flame monitoring in industrial burners with semiconductor-based UV sensors focusing on hydrogen-flame

Abstrait
Using semiconductor based sensors for flame detection, such as presented with this article can be regarded as a fascinating approach not just with regards on costs and safety. Additionally, looking at environmental and sustainability aspects using semiconductor sensors instead of discharge tubes is a useful tool towards durability and longevity. The possibility of working with two different sensor chips for two different kind of irradiadion (UV and IR) in one small size sensor housing opens up a multitude of new and interesting application possibilities.

Dr. Niklas Papathanasiou, sglux GmbH, Berlin, Germany

Sensor Magazin 2/2024 (c) Magazin Verlag

Abstract
For more than 20 years, the Berlin-based company sglux GmbH has been producing photodiodes and sensors for measuring UV radiation, as used in many areas of industrial production, medical technology, combustion control and for monitoring UV disinfection processes. The precise detection of the ultraviolet irradiance is of great importance for a controlled and efficient functioning. sglux solves these tasks with SiC-based photodiodes, since 2009 from in-house semiconductor production. SiC photodiodes have an advantage in the detection of UV radiation due to their high band gap of 3.26 eV, as they are insensitive to visible and near-infrared radiation. In addition, SiC photodiodes have very low dark currents, so that even the smallest amounts of radiation can be detected. In the measurement of strong UV radiation, SiC scores with its high resistance to degradation.

Michael Schraml¹, Alexander May¹, Dr. Tobias Erlbacher¹, Dr. Niklas Papathanasiou², Dr. Tilman Weiss²,
¹Fraunhofer IISB, Erlangen, Germany
²sglux GmbH, Berlin, Germany

Towards SiC-Based VUV Pin-Photodiodes – Investigations on 4H-SiC Photodiodes with Shallow Implanted Al Emitters

Zusammenfassung
4H silicon carbide (SiC) based pin photodiodes with a sensitivity in the vacuum ultraviolet spectrum (VUV) demand newly developed emitter doping profiles. This work features the first ever reported 4H-SiC pin photodiodes with an implanted p-emitter and a noticeable sensitivity at a wavelength of 200 nm. As a first step, Aluminum doping profiles produced by low energy ion implantation in 4H-SiC were characterized by secondary-ion mass spectrometry (SIMS). Photodiodes using these shallow emitters are compared to one with a deep p-emitter doping profile employing IV characteristics and the spectral response. SIMS results demonstrate the possibility of shallow Alimplantation profiles using low implantation energies with all emitter profiles featuring characteristic I-V results. For some shallow doping profiles, a meassurable signal at the upper limit of the VUV spectrum could be demonstrated, paving the way towards 4H-SiC pin photodiodes with sensitivities for wavelengths below 200 nm.

M. Schraml¹, N. Papathanasiou², A. May¹, M. Rommel¹, T. Erlbacher³
¹Fraunhofer IISB, Erlangen, Germany
²sglux GmbH, Berlin, Germany
³Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

2023 IEEE Photonics Conference (IPC) 12. – 16.11.2023

4H-SiC PIN Photodiode for VUV Detection Using an Enhanced Emitter Doping Desig

Abstract
The fabrication of a novel Vacuum UV (VUV) sensitive 4H-SiC pin photodiode is presented. Aluminum ion implantation was used to fabricate a patterned emitter structure with p – and p + regions resulting in the highest reported VUV sensitivity for a SiC pin photodiode.

Dr. Tilman Weiss, sglux GmbH, Berlin, Germany

How to determine the right UV sensor for flame detection?

Abstract
The present article informs about different approaches using UV photodetectors for the detection of a combustion flame (natural gas, hydrogen or oil).

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TOCONs for the detection of fire and combustion burner flames

Dr. Tilman Weiss, sglux GmbH, Berlin, Germany

TOCONs for the detection of fire and combustion burner flames

Abstract
The standard sglux TOCONs are featured by a relatively high time constant that extends from 30 ms (low sensitivity TOCONs) until 80 ms (high sensitivity TOCONs). Most of the TOCON applications benefit from this high time constant because usually the TOCON’s application is to measure a UV irradiation that slowly changes. Such applications are e.g. the control of UV disinfection and UV curing sources. Short changes of signal caused by electromagnetic or high frequency influences are averaged – which is a benefit. However, looking at flame detection in heaters or looking at fire detection applications this relatively high time constant may cause problems. The present report presents opportunities to reduce the dead time of the TOCONs.

Bielefeld, S.E., TU Delft Electrical Engineering, Mathematics and Computer Science
Master Thesis

Abstract
As a contribution to the decarbonisation of domestic heating, the graduation project investigates the feasibility of the application of UV sensor technology for flame detection and flame monitoring in hydrogen-powered domestic gas boilers. The research includes empirical studies and an analytical approach to describe influences on the sensor signal strength.

Luther W. Beegle et al.
Space Sci Rev (2021) 217:58

Perseverance’s Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) Investigation

Abstract
The Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) is a robotic arm-mounted instrument on NASA’s Perseverance rover. SHERLOC has two primary boresights. The Spectroscopy boresight generates spatially resolved chemical maps using fluorescence and Raman spectroscopy coupled to microscopic images (10.1 μm/pixel). The second boresight is a Wide Angle Topographic Sensor for Operations and eNgineering (WATSON); a copy of the Mars Science Labora- tory (MSL) Mars Hand Lens Imager (MAHLI) that obtains color images from microscopic scales (∼13 μm/pixel) to infinity. SHERLOC Spectroscopy focuses a 40 μs pulsed deep UV neon-copper laser (248.6 nm), to a ∼100 μm spot on a target at a working distance of ∼48 mm. Fluorescence emissions from organics, and Raman scattered photons from organics and minerals, are spectrally resolved with a single diffractive grating spectrograph with a spectral range of 250 to ∼370 nm. Because the fluorescence and Raman regions are natu- rally separated with deep UV excitation (<250 nm), the Raman region ∼ 800 – 4000 cm−1 (250 to 273 nm) and the fluorescence region (274 to ∼370 nm) are acquired simultaneously without time gating or additional mechanisms. SHERLOC science begins by using an Aut- ofocus Context Imager (ACI) to obtain target focus and acquire 10.1 μm/pixel greyscale images. Chemical maps of organic and mineral signatures are acquired by the orchestration of an internal scanning mirror that moves the focused laser spot across discrete points on the target surface where spectra are captured on the spectrometer detector. ACI images and chemical maps (< 100 μm/mapping pixel) will enable the first Mars in situ view of the spa- tial distribution and interaction between organics, minerals, and chemicals important to the assessment of potential biogenicity (containing CHNOPS). Single robotic arm placement chemical maps can cover areas up to 7×7 mm in area and, with the < 10 min acquisition time per map, larger mosaics are possible with arm movements. This microscopic view of the organic geochemistry of a target at the Perseverance field site, when combined with the other instruments, such as Mastcam-Z, PIXL, and SuperCam, will enable unprecedented analysis of geological materials for both scientific research and determination of which sam- ples to collect and cache for Mars sample return.

Dr. Tilman Weiss, sglux GmbH, Berlin, Germany

UV sensors for hydrogen flame detection

Abstract
Bei der Arbeit am gesellschaftlichen Ziel der Dekarbonisierung des Energieverbrauchs u.a. auch durch die Substitution von Erdgas durch regenerativ erzeugte Brennstoffe, ist Wasserstoff ein besonders aussichtsreicher Kandidat. Bei der erforderlichen Umrüstung von Erdgas-Thermen stellt die durch die Norm EN298 definierte Überwachung der Brennerflamme eine besondere Herausforderung dar. Stand der Technik ist die Flammenüberwachung mittels Ionisationsfühlern. Dieses Verfahren ist preiswert und zuverlässig. Wird dem Erdgas allerdings Wasserstoff beigemischt oder besteht das Gas ausschließlich aus Wasserstoff, ergibt sich eine andere Reaktionskinetik, welche die Zuverlässigkeit der bisherigen Fühler deutlich reduziert bzw. ihren Einsatz unmöglich macht.

Dieser Herausforderung kann mit UV-Sensoren begegnet werden, die alle Arten von Flammen anhand ihres charakteristischen Emissionsspektrums im UV-Bereich zuverlässig erkennen können. UV-Sensoren sind in der Anschaffung teurer als Ionisationsfühler und werden daher aktuell nur in hochpreisigen Industriebrennern, nicht aber in Haushaltsbrennern eingesetzt. Nach aktuellem Wissensstand gibt es aber bei der Erkennung einer Wasserstoff-Flamme keine Alternative zum UV-Sensor. Unsere UV-Sensoren TOCON_ABC1 und TOCON_ABC2 produzieren wir seit 2006 für den Einsatz in EN298-konformen Erdgas-Feuerungsautomaten. Für die Wasserstoff-Flamme haben wir diese Produkte nun zum neuen TOCON_F weiterentwickelt. Der Unterschied zu TOCONs ABC1 und ABC2 besteht in einer verringerten Off-Totzeit im Fall einer Übersteuerung des Sensors, welche von mehreren 100 Millisekunden auf unter 70 Millisekunden reduziert werden konnte – und zwar unabhängig davon, wie weit der Sensor zum Zeitpunkt des Erlöschens der Flamme ausgesteuert war. Entsprechend konnte die Reaktionsgeschwindigkeit auf das Ausfallen einer Flamme deutlich erhöht werden. Auch wenn TOCONs TOCON_ABC1 und TOCON_ABC2 als Basis EN298-konformer Flammenwächter verwendet werden können (dort wird gefordert, dass der Ausfall einer Flamme spätestens nach 1000 ms eine Unterbrechung der Brennstoffzufuhr bewirken muss), könnte die Normanforderung in Zukunft verschärft werden. Grund hierfür könnte die bei Wasserstoff im Vergleich zu Erdgas um Faktor 8 höhere Flammengeschwindigkeit und der deutlich größere Zündbereich sein. Mit dem TOCON_F können also kürzere Abschaltzeiten als gegenwärtig gefordert realisiert werden. Dadurch ist der Einsatz dieser Bauteile auch bei eventueller Verschärfung der Norm zukunftssicher.

Dr. Niklas Papathanasiou, sglux GmbH, Berlin, Germany

SiC AlGaN Aging Report

Abstract
SiC and AlGaN based UV photodiodes had been irradiated by Hg medium pressure lamps for 90 hours and a UV irradiation intensity of 60mW/cm². The SiC photodiodes showed no measurable degradation whereas the AlGaN photodiodes lost 80 % – 85 % of sensitivity.

D. Prasai¹, W. John¹, L. Weixelbaum¹, O. Krueger¹, G. Wagner², P. Sperfeld³, S. Nowy³, D. Friedrich³, S. Winter³ and T. Weiss⁴,
¹Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Berlin, Germany, ²Leibniz-Institut fuer Kristallzuechtung, Berlin, Germany, ³Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ⁴sglux GmbH, Berlin, Germany

J. Mater. Res., first view (2012).

Abstract
Highly efficient polytype 4H silicon carbide (4H-SiC) p–n diodes for ultraviolet (UV) light detection have been fabricated, characterized, and exposed to high-intensity mercury lamp irradiation (up to 17 mW/cm²). The behavior of the photocurrent response under UV light irradiation using a low-pressure mercury UV-C lamp (4 mW/cm²) and a medium-pressure mercury discharge lamp (17 mW/cm²) has been studied. We report on long-term UV photoaging tests performed for up to 22 mo. Results demonstrate the robustness of SiC photodiodes against UV radiation. The devices under test showed an initial burn-in effect, i.e., the photocurrent response dropped by less than 5% within the first 40 h of artificial UV aging. Such burn-in effect under UV stress was also observed for previously available polytype 6H silicon carbide (6H–SiC) p–n photodetectors. After burn-in, no measurable degradation has been detected, which makes the devices excellent candidates for high irradiance UV detector applications.

S. Nowy¹, B. Barton¹, S. Pape¹, P. Sperfeld¹, D. Friedrich¹, S. Winter¹, G. Hopfenmueller², and T. Weiss²,
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany

Proceedings of NEWRAD2011, edited by S. Park and E. Ikonen. (Aalto University, Espoo, Finland, 2011) p. 203.

Abstract
For monitoring high UV irradiance, silicon carbide (SiC) based photodiodes are used. In this paper we describe the characterization of the novel SiC UV photodiodes in terms of their spectral and integral responsivity. Special attention is paid to the aging behavior of the photodiodes due to high UV irradiance. Artificial aging of the samples is performed by illumination with a high power medium pressure mercury discharge lamp.