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- Källhammer, Jan-Erik, et al.
(author)
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Fulfilling the pedestrian protection directive using a long-wavelength infrared camera designed to meet both performance and cost targets
- 2006
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In: Photonics in the Automobile II. - : SPIE. ; , s. 19809-19809
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Conference paper (peer-reviewed)abstract
- Pedestrian fatalities are around 15% of the traffic fatalities in Europe. A proposed EU regulation requires the automotive industry to develop technologies that will substantially decrease the risk for Vulnerable Road Users when hit by a vehicle. Automatic Brake Assist systems, activated by a suitable sensor, will reduce the speed of the vehicle before the impact, independent of any driver interaction. Long Wavelength Infrared technology is an ideal candidate for such sensors, but requires a significant cost reduction. The target necessary for automotive serial applications are well below the cost of systems available today. Uncooled bolometer arrays are the most mature technology for Long Wave Infrared with low-cost potential. Analyses show that sensor size and production yield along with vacuum packaging and the optical components are the main cost drivers. A project has been started to design a new Long Wave Infrared system with a ten times cost reduction potential, optimized for the pedestrian protection requirement. It will take advantage of the progress in Micro Electro-Mechanical Systems and Long Wave Infrared optics to keep the cost down. Deployable and pre-impact braking systems can become effective alternatives to passive impact protection systems solutions fulfilling the EU pedestrian protection regulation. Low-cost Long Wave Infrared sensors will be an important enabler to make such systems cost competitive, allowing high market penetration.
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2. |
- Lloyd-Spets, Anita, 1951-, et al.
(author)
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Gas sensor device based on Metal-Insulator Silicon carbide-Junction-Field Effect-Transistor
- 2005
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In: Encyclopedia of Sensors, eds.. - California : American Scientific Publishers. - 158883056X ; , s. 171-192
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Book chapter (other academic/artistic)abstract
- The applications of sensors range from medical diagnostics to industrial manufacturing and to defense and national security applications. When an area spans such a large diversity of research, and where research from many different countries is also involved, a review of these developments becomes especially useful. Because it bridges science and technology the field also provides a desired interaction between researchers and research in technologically advanced and developing countries. The present series of volumes, "The Encyclopedia of Sensors" , the first of its kind, is intended to provide a timely compendium of the entire field. As such it can be expected to play a significant role in worldwide future progress and understanding."
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3. |
- Nakagomi, Shinji, et al.
(author)
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Influence of gate bias of MISiC-FET gas sensor device on the sensing properties
- 2005
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In: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 108, s. 501-507
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Journal article (peer-reviewed)abstract
- The influence of gate bias on the gas sensing properties of SiC-based field effect transistors with catalytic gate and a buried short channel has been studied. The drain current-voltage (I-d-V-D) characteristics of the device reveal non-saturation property, which is a consequence of the short channel design. The drain current is larger in hydrogen ambient than in oxygen ambient at the same drain voltage. The threshold voltage decreases with increasing positive gate bias, and increases with increasing negative gate bias. When a positive bias is applied to the gate, the I-d-V-D characteristics reveal a tendency to saturate. A positive gate bias increases the drain voltage response to hydrogen, as compared with a negative applied gate bias. However, a positive gate bias decreases the stability of the device signal. A change in the channel resistivity is the main reason for the change in the electrical properties when a positive gate bias is applied. A physical model that explains the influence of the gate bias has been studied, and the behavior of the barrier height in the channel was estimated by using the temperature dependence of the I-d-V-D characteristics.
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4. |
- Wang, Qin, et al.
(author)
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Multiple functional UV devices based on III-Nitride quantum wells for biological warfare agent detection
- 2009
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In: GALLIUM NITRIDE MATERIALS AND DEVICES IV. - : SPIE. ; , s. 721627-1-721627-9
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Conference paper (peer-reviewed)abstract
- We have demonstrated surface normal detecting/filtering/emitting multiple functional ultraviolet (UV) optoelectronic devices based on InGaN/GaN, InGaN/AlGaN and Al xGa1-xN/AlyGa1-yN multiple quantum well (MQW) structures with operation wavelengths ranging from 270 nm to 450 nm. Utilizing MQW structure as device active layer offers a flexibility to tune its long cut-off wavelength in a wide UV range from solar-blind to visible by adjusting the well width, well composition and barrier height. Similarly, its short cut-off wavelength can be adjusted by using a GaN or AlGaN block layer on a sapphire substrate when the device is illuminated from its backside, which further provides an optical filtering effect. When a current injects into the device under forward bias the device acts as an UV light emitter, whereas the device performs as a typical photodetector under reverse biases. With applying an alternating external bias the device might be used as electroabsorption modulator due to quantum confined Stark effect. In present work fabricated devices have been characterized by transmission/absorption spectra, photoresponsivity, electroluminescence, and photoluminescence measurements under various forward and reverse biases. The piezoelectric effect, alloy broadening and Stokes shift between the emission and absorption spectra in different InGaN- and AlGaN-based QW structures have been investigated and compared. Possibilities of monolithic or hybrid integration using such multiple functional devices for biological warfare agents sensing application have also be discussed.
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