Project R-9204

Development of high-performance ultra-low bandgap copolymers for near-infrared photodetectors. (Research)

Due to their application in night and thermal vision systems, infrared image sensors are truly imaginative. To date, they are produced via the so-called hybrid technology, in which both the detector and the electronic readout are prepared separately and then interconnected at the pixel level. Obviously, this is a time-consuming process, resulting in low throughput and thus high cost, limiting widespread use (e.g. smartphones). A monolithic approach with direct deposition of the detectors on top of the electronic readout can provide a solution. Attempts to apply this technology to the current inorganic low bandgap absorbers were, however, not very successful due to compatibility issues. In this respect, organic semiconductors are very interesting, since they are compatible with almost all surfaces. For UV-VIS light detection, it is already proven that organic photodetectors (OPD's) can match and even surpass the performance of inorganic photodetectors. However, these organic materials generally show limited absorption in the near- IR region. In this project, we aim at a noteworthy contribution to the above challenge by fundamental scientific studies on the photoactive (p-type) materials required for near-IR OPD's. Synthetic procedures toward ultra-low bandgap copolymers will be carefully optimized, with particular attention for material purity and specific material/photodiode properties (IR absorption, miscibility with the n-type material, high mobility and low dark current).

01 October 2018 - 30 September 2020