Thin film color sensors in multichannel technology

Color images are commonly captured with sensor arrays covered with a mosaic of RGB-filters. In spite of the enormous success of CMOS and CCD color cameras, one-chip color imagers suffer form color aliasing or color moire effects. In order to overcome these limitations we have realized color sensors based on vertical integrated thin film structures. The compete color information of the color aliasing free sensor can be detected at the same position of a sensor array without optical filters. The color separation is realized by the wavelength dependent absorption int eh depth of the material. The thin film systems based on amorphous two terminal deices and stacked diodes are fabricated by a low temperature CVD process. The spectral sensitivity of the sensors can be controlled by the optical and optoelectronic properties of the material son one hand and the design of the devices on the other hand. The working principle of thin film sensors will be presented and the different detection concepts will be compared regarding their application in color recognition and digital imaging.

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