CMOS color image sensor with overlaid organic photoelectric conversion layers having narrow absorption band: depression of dark current

We proposed a solid=state image sensor with multi=layered structure on the basis of the combination of a charge read-out circuit with photoelectric conversion layers, which behave in similar fashion to sensitizing dyes in color films. We developed an organic photoelectric conversion layer, which selectively absorbs green light and transmits blue and red lights. By overlaying this layer on a silicon substrate having silicon photodiodes and a read-out circuit, we successfully produced a two-color sensor. Significant reduction in the dark current in the photoelectric conversion layer owing to appropriate carrier-blocking layers made it possible to take pictures with low level of noise.