A hybrid CMOS-imager with a solution-processable polymer as photoactive layer

The solution-processability of organic photodetectors allows a straightforward combination with other materials, including inorganic ones, without increasing cost and process complexity significantly compared with conventional crystalline semiconductors. Although the optoelectronic performance of these organic devices does not outmatch their inorganic counterparts, there are certain applications exploiting the benefit of the solution-processability. Here we demonstrate that the small pixel fill factor of present complementary metal oxide semiconductor-imagers, decreasing the light sensitivity, can be increased up to 100% by replacing silicon photodiodes with an organic photoactive layer deposited with a simple low-cost spray-coating process. By performing a full optoelectronic characterization on this first solution-processable hybrid complementary metal oxide semiconductor-imager, including the first reported observation of different noise types in organic photodiodes, we demonstrate the suitability of this novel device for imaging. Furthermore, by integrating monolithically different organic materials to the chip, we show the cost-effective portability of the hybrid concept to different wavelength regions. Solution-processed organic semiconductor devices present a low-cost alternative to their silicon counterparts, yet their performance is usually not as strong. By replacing silicon with an organic photoactive layer, Baierlet al. present a solution-processed hybrid CMOS-imager with a 100% pixel fill factor.