Ein Team von Wissenschaftlern und Technikern aus dem Fachgebiet der optischen Halbleiterentwicklung gründete 2003 die sglux GmbH. Ihre Arbeit wurde von dem Wunsch angetrieben, im Schulterschluss mit ihren Kunden und in Kooperation mit Forschungsinstituten wissenschaftliche Neuerungen zu erarbeiten und dem Markt der UV-Messkomponenten zugänglich zu machen. In 2004 haben wir als erstes Unternehmen eine TiO2-basierte UV-Photodiode auf den Markt gebracht. Highlights unserer wissenschaftlichen Arbeit sind fraglos die in 2010 erfolgte Etablierung eines Produktionsverfahrens für SiC-basierte UV-Photodiodenchips oder die in 2013 erfolgte Entwicklung des weltweit ersten PTB-zertifizierten Kalibriernormals für starke UV-Strahlung, wie sie beispielsweise bei der Wasserentkeimung erzeugt wird. Die Ergebnisse dieser sowie weiterer Arbeiten sind in den nachfolgenden Reitern aufgelistet. Die Liste unserer Veröffentlichungen finden Sie hier.
Zeitraum: 2023 – 2025
Förderkennzeichen: FZK02P22K030
Zusammenfassung
Entwicklung einer SiC-Avalanche-Photodiode für Anwendungen in der Flammen- und Feuererkennung
Das Fraunhofer IISB und die sglux GmbH haben im Rahmen das KMU-innovativ Projekts die Arbeit an der Entwicklung eines Herstellungsprozesses für eine SiC-basierte Avalanche Photodiode (APD) aufgenommen. Eine APD verstärkt den Photostrom durch den Lawineneffekt (engl. avalanche effect) und weist dadurch im Gegensatz zur einer herkömmlichen SiC-Photodiode eine deutlich höhere Empfindlichkeit auf. Anwendungsgebiete finden sich im Bereich der Flammen- und Feuererkennung.
Ein erfolgreicher Projektabschluss würde eine interessante Alternative zu aktuell gebräuchlichen Gasentladungsröhren schaffen. Diese Röhren sind zwar in der Lage, sehr geringe UV-Strahlung zuverlässig zu detektieren weisen aber Nachteile auf, die bei halbleiterbasierende UV-Detektoren nicht festzustellen sind: Die Gasentladungsröhren sind relativ groß, zerbrechlich, erfordern eine hohe Betriebsspannung und weisen eine kurze Lebensdauer auf.
Erste Prototypen der neuartigen SiC-APD werden Mitte 2024 erhältlich sein.
Zeitraum: 2012 – 2024
Förderkennzeichen: Landwirtschaftliche Rentenbank, 925486
Abstract
Truffles are regarded as delicacies all over the world. However, only few can afford. The price mainly is driven by the laborious harvesting method. Thoroughly trained sniffer dogs relatively ineffectively try to find the truffles in the ground. The present project aims to the development of an innovative electronic truffle detector and tries to offer an affordable and effective instrument for truffle harvesting. The scientific approach is to reliably detect the ultraviolet light emission of the seasoned truffle’s odor signature ((CH3)2S) while exposed to ozone. An inexpensive method of truffle harvesting would allow forest owners a more sustainable forest cultivation. Today the only means of income is the sales of wood. If additionally truffles could be easily harvested and sold, this would allow a more eco friendly cultivation of the threes, not only focussing on fast growing and well selling wood.
Research project within the 20zwanzig initiative „Advanced UV for life“
Zeitraum: 2016 – 2021
Förderkennzeichen: BMBF 03ZZ0123
Abstract
Within the UV-Aging project experimental setups and scientific method are developed to allow a reliable estimation of the degradation behavior of LED and photodiodes as well as components used in these products (glass, diffusors, reflectors, glues, etc.). In the beginning a UV-Aging chamber will be constructed which allows the control of UV light (UV-A, B & C), temperature (up to 170°C) and humidity (95% r.h.).
Zeitraum: 2014 – 2019
Abstract
Measurement and calibration facilities and calibration methods for high UV irradiation will be established within this project. These methods will accord to the calibration procedures of the Physikalisch-Technische Bundesanstalt (PTB) and will allow sglux to offer novel industry-based calibration services. Hereby the project is focussing on the UV curing industry. Based on results of a corporate BMWi ZIM project, reference radiometers and standard sources with high UV irradiation will be optimized for this application field.
Zeitraum: 2016 – 2019
Förderkennzeichen: BMBF 03ZZ0119A
Abstract
This project aims at the development of optics, electronics and software for miniaturized SiC UV spectrometers and camera modules. sglux as the first company worldwide is working on a new product family of Silicon Carbide (SiC) based UV spectrometers (up to 1024 pixel resolution). The advantage of such UV spectrometers results from the extreme radiation hardness and very high visible blindness of SiC compared with Silicon (Si) based UV spectrometers leading to negligible degradation and zero stray light effects caused by visible light. This new spectrometer technology allows precise UV spectrometry also at presence of strong visible light such as UV measurements in the bright sun (e.g. UV Index spectroscopy) or under room light. Another advantage of the SiC UV spectrometer results from the high radiation hardness and low dark current of this material. These features lead to a broader dynamic range of the spectrometer compared with conventional Si based spectrometers. Spectrometers with a 128 pixel resolution are available for evaluation purpose.
Zeitraum: 2017 – 2018
Zusammenfassung
Der UV-Index nach ISO 17166 ist ein Maß für das Risiko eines Sonnenbrands (Erythema solare) bei einer gegebenen solaren UV-Exposition. Erfasst wird der UV-Index mittels Spektroradiometern. Da diese Systeme in Anschaffung und Betrieb hohe Kosten verursachen, ist bei einer geplanten Verdichtung oder Neuanlage meteorologischer Messnetze die Verwendung kleiner, robuster und wartungsarmer UV-Index-Radiometer zu prüfen.
Primär ist hier die Messunsicherheit beider Konzepte zu vergleichen. Bei Spektroradiometern beträgt diese Messunsicherheit ± 5 % (Egli et al.¹). Die hier zusammengefasste Studie ermittelt die Messunsicherheit von UV-Index-Radiometern des Herstellers sglux GmbH. Hierzu wurden in Summe 2073, an unterschiedlichen Stellen der Erde rückführbar ermittelte, Sonnenspektren (UVI 0,5 bis UVI 13,5) in einer Datenbank erfasst. Aus allen Spektren wurde nach der in ISO 17166 benannten Formel der UV-Index errechnet. Der vom UV-Index- Radiometer gemessene Wert wurde durch Integrierung des jeweiligen Sonnenspektrums mit der spektralen Empfindlichkeit von sieben unterschiedlichen UV-Index-Sensoren ermittelt. Der Unterschied dieser sieben Sensoren bestand aus leicht abweichenden spektralen Empfindlichkeiten, die sich aus nicht vermeidbaren Fertigungstoleranzen ergeben. Aus den beiden Werten wurde für jedes einzelne Sonnenspektrum mit sieben unterschiedlichen Sensoren jeweils der UV-Index errechnet. Diese Werte wurden mit dem jeweiligen aus den Angaben der Norm und den Sonnenspektren ermittelten UV-Indizes verglichen und jeweils eine Messabweichung errechnet, in Summe also 14.511 Werte.
Im Ergebnis ist festzustellen, dass die durch Fertigungstoleranzen erzeugten leicht verschiedenen spektralen Empfindlichkeiten keinen messbaren Einfluss auf die Messabweichung haben. Extremwerte der Sonnenspektren wie UV-Indices von unter 0,5 führten aber zu einer deutlichen Messabweichung. Es wurde erkannt, dass diese Messabweichung einer definierbaren Regel folgt. Entsprechend wurde eine Korrekturmatrix entwickelt und in der Firmware des UV-Index-Radiometers hinterlegt. Nach Anwendung dieser Korrekturmatrix konnte die Messabweichung auch bei extrem niedrigen UV-Indizes auf unter ± 5 % reduziert werden.
Die Messabweichung des UV-Index-Radiometers liegt also im gleichen Bereich wie die für Spektroradiometer berichteten Werte. Dieses Ergebnis ermutigt, weitere Untersuchungen anzustellen. In einer aktuell laufenden Untersuchung wird die Winkelabhängigkeit des UV- Index-Radiometers zu einer von der ISO 17166 geforderten Kosinuskurve hin evaluiert und optimiert. Sollten hier ähnlich gute Ergebnisse wie bei der Messung mit Spektroradiometern erzielbar sein, kann das Ergebnis im Feldeinsatz durch Vergleichsmessungen mit Spektroradiometern validiert werden. Im Erfolgsfall könnte das UV-Index-Radiometer als zuverlässige Ergänzung oder sogar Ersatz von Spektroradiometern betrachtet werden. Besonders in Gegenden, in denen kein ausreichend qualifiziertes Personal zum Betrieb der Spektroradiometer vorhanden ist, können UV-Index-Radiometer einen wichtigen Beitrag zur Gewinnung lokaler Werte des UV-Index darstellen.
Zeitraum: 2015
Förderkennzeichen: BMBF 03ZZ0109
Abstract
Before starting this project no laboratory worldwide performed traceable calibration chains for mobile UV reference radiometers. Our work aimed at a scientific evaluation and completion of UV calibration chains realizing a PTB traceability. This goal was reached by systematic evaluation, improvement and completion of an existing measurement method. As a result we now present as the first laboratory worldwide a traceable calibration chain in the ultraviolet region. This new method will be applied by the members of the “advanced UV for life” project where the method serves to determine properties of the new products planned (mainly UV LED) by means of a traceable measurement. Furthermore, this new method will by applied by sglux to determine the properties of own products and products of third parties by means of calibration service.
Zeitraum: 2011-2013
Förderkennzeichen: BMWi ZIM EP 102409
Abstract
A 128 pixel SiC UV spectrometer with a wavelength resolution of 2.3nm/pixel was development. The advantage of such kind of UV spectrometers result from the extreme radiation hardness and very high visible blindness of SiC compared with Si based UV spectrometers leading to zero stray light effects caused by visible light. This new spectrometer technology allows precise UV spectrometry in the presence of strong visible light such as UV measurements in the bright sun or under room light. Another advantage of the SiC based UV spectrometer results from the high radiation hardness and low dark current of this material. This features lead to a broader dynamic range of the spectrometer compared with conventional Si based spectrometers.
Zeitraum: 2010 – 2012
Förderkennzeichen: BMWi ZIM 2194602RR9
Abstract
Processes like UV water purification or UV hardening require high intensity UV radiation where a traceable calibration did not exist. German sglux GmbH together with PTB (Physikalisch-Technische Bundesanstalt, German national metrology institute) developed the world’s first traceable calibration standard for high irradiation level, in particular for UV water purification sensor calibration
Veröffentlichungen
B. Barton¹, P. Sperfeld¹, A. Towara¹, G. Hopfenmueller², ¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany „Developing and setting up a calibration facility for UV sensors at high irradiance rates“ EMEA Regional Conference, Karlsruhe, Germany (2013)
P. Sperfeld¹, B. Barton¹, S. Pape¹, G. Hopfenmueller²,
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany
„Traceable spectral irradiance measurements at UV water disinfection facilities“
EMEA Regional Conference, Karlsruhe, Germany (2013)
G. Hopfenmueller¹, T. Weiss¹, B. Barton², P. Sperfeld², S. Nowy², S. Pape², D. Friedrich², S. Winter², A. Towara², A. Hoepe², S. Teichert²,
¹sglux GmbH, Berlin, Germany, ²Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany
„PTB traceable calibrated reference UV radiometer for measurements at high irradiance medium pressure mercury discharge lamps“
EMEA Regional Conference, Karlsruhe, Germany (2013)
P. Sperfeld¹, B. Barton¹, S. Pape¹, A. Towara¹, J. Eggers², G. Hopfenmueller³,
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), Germany, ²DVGW-Technologiezentrum Wasser, Karlsruhe, Germany, ³sglux GmbH, Berlin, Germany
„Spectral irradiance measurement and actinic radiometer calibration for UV water disinfection“
Metrologia, issue 51 (2014), S. 282-288.
P. Sperfeld¹, B. Barton¹, S. Pape¹, A. Towara¹, J. Eggers², G. Hopfenmueller³,
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), Germany, ²DVGW-Technologiezentrum Wasser, Karlsruhe, Germany, ³sglux GmbH, Berlin, Germany
„Spectral Irradiance Measurement and Actinic Radiometer Calibration for UV Water Disinfection“
Proceedings of NEWRAD 2014, edited by S. Park, P. Kaerhae and E. Ikonen. (Aalto University, Espoo, Finland 2014) p. 128.
Zeitraum: 2011
Förderkennzeichen: BMWi ZIM 2194602RR9
Zusammenfassung
A detailed study of different properties of UV diffusers was performed. Diffusers are essential components of UV radiometers used as transfer standards. They improve the insensitivity to differing radiation situations.
Veröffentlichungen
Barton¹, B., Sperfeld¹, P., Nowy¹, S., Towara¹, A., Hoepe¹, A., Teichert¹, S., Hopfenmueller², G., Baer³, M. and Kreuzberger³, T. ¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany, ³SGIL Silicaglas GmbH, Langewiesen, Germany
„Characterisation of new optical diffusers used in high irradiance UV radiometers“
Proceedings of NEWRAD2011, edited by S. Park and E. Ikonen. (Aalto University, Espoo, Finland, 2011) p. 278.
Zeitraum: 2011
Förderkennzeichen: BMWi ZIM 2194602RR9
Abstract
For monitoring high UV irradiance, silicon carbide (SiC) based photodiodes are used. This project characterized novel SiC UV photodiodes in terms of their spectral and integral responsivity. Special attention was paid to the aging behavior of the photodiodes due to high UV irradiance. Artificial aging of the samples were performed by illumination with a high power medium pressure mercury discharge lamp. After burn in no degradation could be measured.
Veröffentlichungen
S. Nowy¹, B. Barton¹, S. Pape¹, P. Sperfeld¹, D. Friedrich¹, S. Winter¹, G. Hopfenmueller², T. Weiss²,
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany
„Characterisation of SiC photodiodes for high irradiance UV radiometers“
Proceedings of NEWRAD2011, edited by S. Park and E. Ikonen. (Aalto University, Espoo, Finland, 2011) p. 203.
Zeitraum: 2008- 2010
Förderkennzeichen: BMWi ZIM 2194601DB9
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. Long-term UV photoaging tests had been performed for up to 22 months. 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. Veröffentlichung
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 „Highly reliable Silicon Carbide photodiodes for visible-blind ultraviolet detector applications“
J. Mater. Res., first view (2012).
Zeitraum: 2008-2009
Förderkennzeichen: BMBF 13N9586
Abstract
Electronic and photoelectrical properties of semiconducting titanium dioxide layers had been investigated and improved.
Veröffentlichung C. Nitschke
„Electronic and photoelectrical properties of semiconducting titanium dioxide layers“
Beuth Hochschule für Technik, Master Thesis, 2009
High speed measurement with UV photodiodes – approaches and limits
Zusammenfassung
Usually, the measurement of ultraviolet light is a “steady source” measurement which means that the signal to be measured does not rapidly change in irradiance over time. However, sometimes fast changes of the light intensity need to be measured. This report explains the approaches and limits.
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
Zusammenfassung
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.
Zusammenfassung
Sensor Magazin 4/2024 (c) Magazin Verlag
UV-Strahlung wird in vielen Bereichen der industriellen Fertigung, in medizintechnischen Geräten und zur Desinfektion eingesetzt. Die präzise Messung der Bestrahlungsstärke ist für eine kontrollierte und effiziente Nutzung der UV-Strahlung wichtig. Die für diese Anwendungen eingesetzten UV-Messgeräte müssen in der Lage sein die UV-Bestrahlungsstärke über 13 Größenordnungen hinweg, von wenigen pW/cm² bis zu 10 W/cm² zuverlässig, reproduzierbar und rückführbar zu messen. Hier spielen Digitale Mess-Sonden ihre Stärken aus.
¹sglux GmbH, Berlin, Germany
²Boston Electronics Corporation, Brookline, USA
Journal Contribution to the IUVA UV Solutions Magazine (c) IUVA
Sensor Magazin 2/2024 (c) Magazin Verlag
Zusammenfassung
Das Berliner Unternehmen sglux GmbH produziert seit mehr als 20 Jahren Photodioden und Sensoren zur Messung von UV-Strahlung, wie sie in vielen Bereichen der industriellen Fertigung, der Medizintechnik, der Feuerungstechnik und zur Entkeimungsüberwachung zum Einsatz kommen. Die präzise Erfassung der ultravioletten Bestrahlungsstärke ist für eine kontrollierte und effiziente Funktionsweise von hoher Bedeutung. sglux löst diese Aufgaben mit SiC-basierten Photodioden, seit 2009 aus eigener Halbleiterproduktion. Bei der Detektion von UV-Strahlung sind SiC-Photodioden aufgrund ihrer hohen Bandlücke von 3.26 eV im Vorteil, da sie gegenüber sichtbarer und nah-infraroter Strahlung blind sind. Zudem weisen SiC-Photodioden sehr niedrige Dunkelströme auf, sodass auch kleinste Strahlungsmengen nachgewiesen werden können. Im Bereich der Messung starker UV-Strahlung punktet SiC mit seiner hohen Degradationsfestigkeit.
InterAqua Japan 01. – 03.02.2023
Approaches of LED in-line measurements and its traceable calibration
Zusammenfassung
UV measurement at UV LED arrays.
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
Zusammenfassung
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.
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.
How to determine the right UV sensor for flame detection?
Zusammenfassung The present article informs about different approaches using UV photodetectors for the detection of a combustion flame (natural gas, hydrogen or oil).
¹Division of Organic Trace Analysis and Food Analysis, Bundesanstalt für Materialforschung und -Prüfung, Berlin, Germany
²sglux GmbH, Berlin, Germany
*Authors to whom correspondence should be addressed.
Marker Substances in the Aroma of Truffles
Zusammenfassung
The aim of this study was to identify specific truffle marker substances within the truffle aroma. The aroma profile of different truffle species was analyzed using static headspace sampling with gas chromatography mass spectrometry analysis (SHS/GC-MS). Possible marker substances were identified, taking the additional literature into account. The selected marker substances were tested in an experiment with 19 truffle dogs. The hypothesis “If trained truffle dogs recognize the substances as supposed truffles in the context of an experiment, they can be regarded as specific” was made. As it would be nearly impossible to investigate every other possible emitter of the same compounds to determine their specificity, this hypothesis was a reasonable approximation. We were interested in the question of what it is the dogs actually search for on a chemical level and whether we can link their ability to find truffles to one or more specific marker substances. The results of the dog experiment are not as unambiguous as could have been expected based on the SHS/GC-MS measurements. Presumably, the truffle aroma is mainly characterized and perceived by dogs by dimethyl sulfide and dimethyl disulfide. However, as dogs are living beings and not analytical instruments, it seems unavoidable that one must live with some degree of uncertainty regarding these results.
Space Sci Rev (2021) 217:58
Perseverance’s Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) Investigation
Zusammenfassung
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.
Master Thesis
Zusammenfassung
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.
TOCONs für die Brennerflammen- und Feuererkennung
Zusammenfassung
Unsere Standard-TOCONs haben eine relativ hohe Zeitkontante. Diese erstreckt sich von 30 ms für TOCONs mit geringer Empfindlichkeit bis zu 80 ms bei TOCONs mit hoher Empfindlichkeit. Diese Reaktionszeit ist für die meisten Messanwendungen eine gute Voraussetzung zur präzisen Erfassung des Mess-Signals. Normalerweise geht es darum, langsam veränderliche Signale zuverlässig zu messen. Die o.g. Zeitkonstanten bewirken, dass kurzfristige Signaländerungen oder hochfrequente Signal-Anteile gemittelt in das Mess-Signal eingehen. So kann die von der zu messenden Quelle ausgehende Strahlung im Hinblick auf ihre Wirkung (z.B. Entkeimung oder Lackhärtung) gut ermittelt werden. Bei der Flammenüberwachung in Heizbrennern und bei der Feuererkennung ist die für die Standard-Anwendungen vorteilhafte hohe Zeitkonstante von Nachteil. Dieser Bericht zeigt Möglichkeiten der Reduktion der Reaktionszeiten.
UV-Sensoren zur Überwachung der UVC-Oberflächenentkeimung
Zusammenfassung
Bei der Entkeimung von Oberflächen in Artzpraxen, Krankenzimmern, Apotheken aber auch in der Lebensmittel- und Medikamentenproduktion sowie öffentlich zugänglichen Sanitärbereichen kommt neben chemischen Verfahren auch UVC-Strahlung zum Einsatz. Bei diesen Anwendungen ist die UV-Strahlung entweder am Ort der Erzeugung oder am Wirkort oder an beiden Orten zu erfassen. So kann die zur sicheren Keimabtötung mindestens erforderliche Dosis hinreichend genau ermittelt werden. Der Bericht liefert weitere Details und stellt geeignete Mess-Produkte aus dem sglux-Sortiment vor.
SiC Temperature Coefficient
Zusammenfassung
This report assigns the temperature coefficient (TC) of sglux SiC-photodiodes in relation to the incident wavelength. It demonstrates that the temperature coefficient is slightly negative for incident wavelengths below 270nm. At appox. 270nm is it almost zero and then strongly rises towards positive values with increasing wavelengths. The report further explains the physical background of this phenomena.
Technical Report „Where SiC can replace discontinued GaP?“
Zusammenfassung
For measurement applications with a peak radiation between 210 nm and 346 nm (e.g. UV sterilization lamp or combustion flame control) a SiC UV photodiode can replace a GaP photodiode without restrictions – it will even output a higher photocurrent. A SiC device irradiated with a peak radiation from 346 to 380 nm will output a lower photocurrent compared with GaP (at same active area). However, if the radiation intensity is high, e.g. curing applications at 365 nm the SiC’s current output will remain at a usable level.
¹LACy, Laboratoire de l’Atmosphère et des Cyclones (UMR 8105 CNRS, Université de La Réunion, Météo-France), 97744 Saint-Denis de La Réunion, France.
²School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4041, South Africa.
³Laboratoire d’Optique Atmosphérique, Université Lille, CNRS, UMR 8518, F-59000 Lille, France.
⁴Observatoire des Sciences de l’Univers de la Réunion, UMS 3365, 97744 Saint-Denis de la Réunion, France.
⁵Reuniwatt, 97490 Sainte Clotilde de la réunion, France.
⁶Department of Geography, Geo-informatics and Meteorology, University of Pretoria, Pretoria 0002, South Africa.
⁷Environment and Health Research Unit, South African Medical Research Council, Pretoria 0001, South Africa.
Int J Environ Res Public Health. 2020 Apr 21;17(8):2867. doi: 10.3390/ijerph17082867
Zusammenfassung
Measurement of solar ultraviolet radiation (UVR) is important for the assessment of potential beneficial and adverse impacts on the biosphere, plants, animals, and humans. Excess solar UVR exposure in humans is associated with skin carcinogenesis and immunosuppression. Several factors influence solar UVR at the Earth’s surface, such as latitude and cloud cover. Given the potential risks from solar UVR there is a need to measure solar UVR at different locations using effective instrumentation. Various instruments are available to measure solar UVR, but some are expensive and others are not portable, both restrictive variables for exposure assessments. Here, we compared solar UVR sensors commercialized at low or moderate cost to assess their performance and quality of measurements against a high-grade Bentham spectrometer. The inter-comparison campaign took place between March 2018 and February 2019 at Saint-Denis, La Réunion. Instruments evaluated included a Kipp&Zonen UVS-E-T radiometer, a Solar Light UV-Biometer, a SGLux UV-Cosine radiometer, and a Davis radiometer. Cloud fraction was considered using a SkyCamVision all-sky camera and the Tropospheric Ultraviolet Visible radiative transfer model was used to model clear-sky conditions. Overall, there was good reliability between the instruments over time, except for the Davis radiometer, which showed dependence on solar zenith angle. The Solar Light UV-Biometer and the Kipp&Zonen radiometer gave satisfactory results, while the low-cost SGLux radiometer performed better in clear sky conditions. Future studies should investigate temporal drift and stability over time.
UV sensors for hydrogen flame detection
Zusammenfassung
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.
SiC AlGaN Aging Report
Zusammenfassung
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.
Tech Report 350°C
Zusammenfassung
Neue Hochtemperatur SiC-Photodioden erhältlich. Die Photodioden können permanent bis zu einer Temperatur von 350°C betrieben werden.
sglux GmbH, Berlin, Germany
Presentation on IoT-SNAP2018: IoT Enabling Sensing/Network/AI and Photonics Conference at Optics & Photonics Intenational Congress OPIC 2018, Pacifico Yokohama, Yokohama, Japan
Zusammenfassung
In this contribution we report about SiC based UV photodiodes as the core component of smart UV sensors for various medical applications. In dialysis machines the transparency of urea is monitored by a SiC UV photodiode based UV transmission measurement module. A photodiode combined with an optical filter which reproduces the erythermal action spectrum helps Lupus patients to monitor their daily dose of solar UV radiation. sglux UVC sensor “UV-Safester” is a smartphone based tool to detect harmful UV radiation at a workplace employing the ICNIRP regulation. A wireless UV sensor module monitors the UV disinfection applied by disinfection robots in operating rooms.
sglux GmbH, Berlin, Germany
Presentation on International Conference on UV LED Technologies & Applications 2018, Berlin, Germany
Abstract
Artificial UV radiation is applied in many processes such as UV disinfection, UV curing or biological activation. Besides discharge tubes, LEDs are becoming more important for a rising number of applications in particular UV curing or medical treatment. In general, exposure to UV radiation may cause health problems such as skin aging, eye damage or skin cancer. The potential danger varies with the irradiated wavelengths and the exposure time. The limits and the spectral weighting function of the UV irradiance are given in the directive 2006/25/EC published by the European Comission. The hereby submitted lecture will introduce a radiometer that precisely evaluates the hazard potential while displaying the maximum daily exposition time at a certain measurement point. The digital SiC based UV sensor has a spectral responsivity close to the biological weighting function and is calibrated to different UV LEDs with typical half widths. The sensor can be connected to any Android smartphone.
¹sglux GmbH, Berlin, Germany, ²Technische Universität Bergakademie Freiberg, Germany
50. Jahrestagung des Fachverbandes Strahlenschutz 2018, Dresden
Zusammenfassung
Umweltdaten müssen erfasst werden, um die Lebensqualität und die Gesundheit der Bevölkerung zu erhalten und zu verbessern. Dabei leistet der solare UV-Index (UVI) einen wichtigen Beitrag, indem er Schutzbeauftragten und Privatpersonen Hinweise für Schutzmaßnahmen und eine angemessene Aufenthaltszeit in der Sonne gibt. In Deutschland wird der UV-Index durch das vom Bundesamt für Strahlenschutz koordinierte UV-Messnetz an 10 Standorten mittels in Anschaffung und Betrieb aufwändiger Spektralradiometer erfasst. Mit robusten und wartungsarmen UV-Radiometern könnte eine gebotene Verdichtung dieses Messnetzes kostengünstig realisiert werden. Dafür müssen diese Radiometer die erytheme Wirkungsfunktion nach ISO 17166 präzise nachbilden.
In diesem Beitrag wird der Einfluss von verschiedenen Sonnenspektren und von produktionsbedingten Variationen auf die Messunsicherheit der UV-Index-Messungen mittels SiC-basierter UV-Index-Radiometer (SiC-UVI-Radiometer) untersucht und mit den von Spektralradiometern ermittelten Ergebnissen verglichen.
Es konnte gezeigt werden, dass SiC-UVI-Radiometer in einem weiten Messbereich eine sehr geringe Messunsicherheit von ±5 % erzielen können, und damit mit der Messunsicherheit von Spektralradiometern (ebenfalls ±5 %) vergleichbar sind. Dazu wurde aus der Simulation von UVI-Messungen mit über 2000 verschiedenartigen Sonnenspektren eine für SiC-basierte UVI-Radiometer gültige Diskrepanz-Korrekturfunktion ermittelt.
¹University of Veterinary Medicine, Unit of Physiology and Biophysics, Vienna, Austria, ²PMOD/WRC, Davos Dorf, Switzerland, ³Medical Univ. Innsbruck, Innsbruck, Austria, ⁴Royal Meteorological Institute of Belgium, Observations, Brussels, Belgium, ⁵Royal Belgian Institute for Space Aeronomy, Brussels, Belgium, ⁶Bulgarian Academy of Sciences, Stara Zagora, Bulgaria, ⁷Metorological and hydrological institute of Croatia, Metorological and hydrological institute of Croati, Croatia, ⁸Czech Hydrometeorological Institute, Solar and Ozone Department, Hradec Kralove, Czech Republic, ⁹Danish Meteorological Institute, Copenhagen, Denmark, ¹⁰Tartu Observatory, Tartumaa, Estonia, ¹¹Finnish Meteorological Institute, Helsinki, Finland, ¹²Météo-France, Toulouse Cedex, France, ¹³Bundesamt fur Strahlenschutz Neuherberg, Section for Optical Radiation, Neuherberg, Germany, ¹⁴sglux GmbH, Berlin, Germany, ¹⁵Aristotle University of Thessaloniki, Greece, ¹⁶Hungarian Meteorological Service, Marczell György Main Observatory, Budapest, Hungary, ¹⁷Sapienza Universita’ di Roma, Physics Department, Rome, Italy, ¹⁸ISPRA, Physical Agents Unit, Rome, Italy, ¹⁹ARPA Valle d’Aosta loc, Saint-Christophe, Italy, ²⁰LaMMA Consortium, Institute of Biometeorology of the National Research Council, Sesto Fiorentino, Italy, ²¹CNR-IBIMET, Florence, Italy, ²²ARPA di Vicenza, Vicenza, Italy, ²³National Research Council, Institute of Atmospheric Sciences and Climate, Bologna, Italy, ²⁴ENEA, Laboratory for Observations and Analyses of the Earth and Climate, Rome, Italy, ²⁵Lycée Classique de Diekirch, Computarium and meteoLCD, Diekirch, Luxembourg, ²⁶University of Malta, Institute for Sustainable Energy, Marsaxlokk, Malta, ²⁷Institute of Applied Physics of the Academy of Sciences of Moldova, Kishinev, Moldova (the Republic of), ²⁸Dutch National Health Institute (RIVM), Netherlands, ²⁹NILU – Norwegian Institute for Air Research, Kjeller, Norway, ³⁰University of Oslo, Institute of Physics, Oslo, Norway, ³¹Statens Stralevern, Monitoring and Research, Oesteras, Norway, ³²Institute of Meteorology and Water Management, Gdynia, Poland, ³³Institute of Geophysics, Polish Academy of Sciences, Warszw, Poland, ³⁴Instituto Português do Mar e da Atmosfera, Observatório Afonso Chaves, Ponta Delgada S. Miguel, Portugal, ³⁵Moscow State University, Moscow, Russian Federation, ³⁶University of Belgrade, Zemun, Serbia, ³⁷University of Novi Sad, Novi Sad, Serbia, ³⁸Slovenian Environment Agency, Ljubljana, Slovenia, ³⁹Slovakian Academy of Sciences, Tatranska Lomnica, Slovakia, ⁴⁰Spanish Meteorological Agency, Area of Atmospheric Observation Networks, Madrid, Spain, ⁴¹University of Valladolid, Valladolid, Spain, ⁴²National Institute for Aerospace Technology, Mazagon, Spain, ⁴³University of Extremadura, Department of Physics, Badajoz, Spain, ⁴⁴SMHI, Norköpping, Sweden, ⁴⁵MeteoSwiss, Atmospheric data division, Payerne, Switzerland, ⁴⁶University of Manchester, Manchester, United Kingdom of Great Britain and Northern Ireland, ⁴⁷Public Health England Centre for Radiation Chemical and Environmental Hazards, Radiation Dosimetry, Didcot, United Kingdom of Great Britain and Northern Ireland
Journal: Photochemical & Photobiological Sciences, Publisher: The Royal Society of Chemistry.
Abstract
The UV Index was established more than 20 years ago as a tool for sun protection and health care. Shortly after its introduction, UV Index monitoring started in several countries either by newly acquired instruments or by converting measurements from existing instruments into the UV Index. The number of stations and networks has increased over the years. Currently, 160 stations in 25 European countries deliver online values to the public via the Internet. In this paper an overview of these UV Index monitoring sites in Europe is given. The overview includes instruments as well as quality assurance and quality control procedures. Furthermore, some examples are given about how UV Index values are presented to the public. Through these efforts, 57% of the European population is supplied with high quality information, enabling them to adapt behaviour. Although health care, including skin cancer prevention, is cost-effective, a proportion of the European population still doesn’t have access to UV Index information.
sglux GmbH, Berlin, Germany
Presentation on IUVA World Congress Spotlights Water Disinfection Technologies 2017, Dubrovnik, Croatia
Abstract
In UV water purification applications UV sensors are monitoring the dosage of UV irradiation as according to ÖNORM and DVGW standards. sglux GmbH is manufacturing such sensors employing opaque synthetic quartz-glass diffusers as entrance windows. This paper investigates the influence of high-intensity UV irradiation on the transmission behavior of these diffusers. Quartz-glass and micro-porous quartz-glass were investigated. The sensors were continuously monitored while irradiated by a 1kW medium pressure Hg lamp with a total UV irradiance of 1000mW/cm² for 800 hours. Before and after the aging period the total transmissions of the diffusers were measured.
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), Germany, ²DVGW-Technologiezentrum Wasser, Karlsruhe, Germany, ³sglux GmbH, Berlin, Germany
Proceedings of NEWRAD 2014, edited by S. Park, P. Kaerhae and E. Ikonen. (Aalto University, Espoo, Finland 2014) p. 128.
Abstract In a joint project, sglux and PTB investigated and developed methods and equipment to measure the spectral and weighted irradiance of high-efficiency UV-C emitters used in water disinfection plants. A calibration facility was set up to calibrate the microbicidal irradiance responsivity of actinic radiometers with respect to the weighted spectral irradiance of specially selected Hg low-pressure and medium-pressure UV radiators. To verify the calibration and to perform on-site tests, spectral measurements have been carried out directly at water disinfection plants in operation. The weighted microbicidal irradiance of the plants was calculated and compared to the measurements of various actinic radiometers.
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany
EMEA Regional Conference, Karlsruhe, Germany (2013)
Abstract PTB provides spectral irradiance calibrations traceable to national primary standards and the SI system. A transfer standard source for high UV irradiances has been constructed and characterized. A medium pressure Hg lamp and a low pressure Hg lamp provide different spectra at different irradiance levels. The system might serve as a calibration facility for DVGW & ÖNORM conform UV sensors. Calibration by direct substitution to reference sensors can be carried out.
¹sglux GmbH, Berlin, Germany, ²Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany
EMEA Regional Conference, Karlsruhe, Germany (2013)
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany
EMEA Regional Conference, Karlsruhe, Germany (2013)
Abstract PTB provides spectral irradiance calibrations traceable to national primary standards and the SI system. Transportable spectroradiometer systems have been adapted for high UV irradiance measurements. Successful measurements at medium pressure Hg and low pressure Hg lamp facilities have been carried out. The effective microbicidal irradiances agree within 15%. 40° sensor geometry could be developed. Discussion about calibration service and support.
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.
¹Physikalisch-Technische Bundesanstalt Braunschweig und Berlin (PTB), 4.1 Photometry and Applied Radiometry, Braunschweig, Germany, ²sglux GmbH, Berlin, Germany, ³SGIL Silicaglas GmbH, Langewiesen, Germany
Proceedings of NEWRAD2011, edited by S. Park and E. Ikonen. (Aalto University, Espoo, Finland, 2011) p. 278.
Abstract
Diffusers are essential components of UV radiometers used as transfer standards. They improve the insensitivity to differing radiation situations. In combination with a beam limiting aperture, a diffuser defines the irradiated area [1]. A detailed study of different properties of UV diffusers is shown.
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.
Beuth Hochschule für Technik, Master Thesis, 2009
Master thesis 2009
Abstract
In the present thesis electronic and photoelectrical properties of semiconducting titanium dioxide layers were measured using different measuring methods. The titanium dioxide layers had been produced using the sol-gel-process with different precursor solutions. The findings and insights gained shall be used to manipulate the structure and functionality of UV-photodiodes with titanium-dioxide-layers. Traps had been proven both by the analysis of the spectral resolution of the photocurrent and thermally stimulated luminescence. These traps are affected by the titanium dioxide-layer manufacturing process. Using the impedance spectroscopy, the UV-photodiodes inner structure, the width of the space charge layer and the electrical conduction of the titanium dioxide-layer grains and grain boundaries could be measured. Between the impedance of the UV-photodiodes and the speed of reaction a correlation could be noticed. Additionally voltage dependent current and capacity measurements had been carried out as well as thermally stimulated currents had been measured.
JOURNAL OF APPLIED PHYSICS 98, 104501 (2005)
Abstract
Pt/TiO2/Ti Schottky diodes were investigated by current-voltage analysis, photoresponse, and transient photocurrent(PC) in a wide temperature range. The compact TiO2 as well as the SiO2 passivation layers were prepared by the sol-gel technique. The Schottky-barrier height (1.2–1.3eV) was equal to the difference of the work functions of Pt and Ti. The temperature dependence of the ideality factor was interpreted in terms of a Gaussian distribution of barrier heights [J. H. Werner and H. H. Güttler, J. Appl. Phys.69, 1522 (1991)]. Space-charge-limited currents under the presence of defects with an exponential distribution were observed. Under zero-potential condition, the PC transients were practically independent of temperature and the electron drift mobility amounted to 2× 10E-4 cm² (Vs)
A screening dipole layer at the Pt/TiO2 junction was formed under low forward and reverse potentials. Defects were generated under electron injection.