Fujifilm was recently granted a patent for a sensor that uses a photo sensitive organic (carbon based) film on top of silicon substrate with circuitry for electron readout. The organic coating converts photons impacting the sensor directly to electrons, unlike CCD and CMOS sensor that use silicon photodiodes to convert photons to electrons.
The electrons produced are read by circuitry embedded in the silicon substrate, just as in the case with traditional CCD and CMOS sensors.
The organic film allows practically the entire surface area of sensor to be used for sensing light (100% aperture), which is not the case with traditional sensors.
The extremely thin organic layer is able to absorb enough light making the sensor free from spectral cross-talk between tiny pixels when capturing slanting rays of light. As a result, there is no need for microlenses to gather incident light as in traditional sensors, which dramatically reduces manufacturing cost.
The organic film based sensor is sensitive only to visible light, unlike traditional sensors, which are also sensitive to IR mandating the use of an IR filter. 
The most compelling advantage of the organic sensor is: It allows small sized sensors to perform better, because with photodiodes there is a limit to how small a pixel can be without unacceptable losses in its sensitivity.
Smallest pixel size is already down to 1.4 µm and despite unrelenting efforts to reduce it further, there is clearly a limit. Organic CMOS Image Sensor for Reduction in Pixel Size
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