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.
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.
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.
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.
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
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.