A new CLSP sensor for Image recognition and color separation

摘要

Large area p-i-n a-SiC:H heterostructures are used as LSP color sensors. For reading out the color signals, three appropriated voltages have to be successively applied in order to combine afterwards the information to yield a color image. The highly resistive and wide band gap doped layers confine the photogenerated carriers at the illuminated regions and driven by the scanner extract information on the image shape and intensity. The bias voltage controls the potential profile across the main generation region leading to color sensitivity. As the positive applied voltage increases the reversed electrical field in the bulk shifts toward the main generation regions, and successively suppresses the ac component of the photocurrent at each primary color allowing color extraction. The device performance is analyzed and the scanning technique for color separation improved. The influence of the optical and electrical bias on image contrast, resolution and color extraction is discussed. A physical model for image and color recognition is presented and supported by a two dimensional simulation.