Embedded UV Combustion Sensor

AstroPower proposes to develop gallium phosphide (GaP) ultraviolet (UV) sensors for engine combustion control. The UV spectra from the free radial combustion components correlates with combustion effectivity in terms of predetonation, and provides a real time basis for central control of excess air ratio, internal combustion temperatures, and other fuel injector parameters. A system for the engine and powertrain control using this sensing method is expected to provide a remarkable improvement in engine performance characteristics. These GaP UV combustion sensors have the advantages of low cost, high sensitivity to ultraviolet light, insensitivity to visible light, and excellent tolerance to high temperatures commonly encountered in internal combustion engine compartments. Detector diodes fabricated using liquid-phase epitaxy show excellent dark current and visible-blind performance; high bandgap GaP material leads to enhanced high-temperature operation up to 500-600 degrees C. The high material quality of GaP and the low-cost of device fabrication lead to significant economic advantages over other high bandgap candidates, such as silicon carbide. Anticipated Benefits/Potential Applications - The visible-blind gallium phosphide UV sensor with excellent high-temperature reliability would have numerous applications in astronomy, high-energy physics, medicine, chemical processing, and other optical analytcal measurement methods. Integration can lead to UV-sensitive CCD detector arrays, with tremendous potential for area-surveillance and safety monitoring. This technology, when fully developed, has large benefits where selectivity, reliability, speed, low-cost, and noise-immunity are required.