The present invention provides a MOS or CMOS based active sensor array for producing electronic images from charge producing light. Each pixel of the array includes a layered photodiode for converting the light into electrical charges and MOS and/or CMOS pixel circuits located under the layered photodiodes for collecting the charges. The present invention also provides additional MOS or CMOS circuits in and/or on the same crystalline substrate for processing the collected charges for the purposes of producing images. The layered photodiode of each pixel is fabricated as continuous layers of charge generating material on top of the MOS and/or CMOS pixel circuits so that extremely small pixels are possible with almost 100 percent packing factors. In preferred embodiments, pixel crosstalk is minimized by careful design of the bottom photodiode layer with the addition of carbon to the doped amorphous silicon N or P layer to increase the electrical resistivity. The increased electrical resistivity also helps avoid adverse electrical effects at the edge of the pixel array where the pixel electrodes may be in close proximity to the material used for a top transparent electrode layer.
