Ultra-high gain-bandwidth product of photomultiplication-type organic photodiodes via interfacial electrostatic interactions
발표자
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초록
내용
For an unprecedentedly high external quantum efficiency (EQE) of photomultiplication-type organic photodiode (PM-OPD), a cationic polyelectrolyte, PFN–Br is employed as a work function modifying layer of ITO to construct a Schottky junction with a donor polymer semiconductor. The resulting EDL at Schottky junction interface induces electrostatic interactions between the exposed cations of the PFN–Br and the trapped electrons which can stabilize the trapped electron states within the isolated acceptor domains. The resulting PM-OPD shows unprecedented performances with EQE of 2,210,000%, responsivity of 11,200 A/W, and specific detectivity of 2.82 × 1014 Jones as well as high reproducibility. In addition, thanks to low surface energy property of PFN–Br, highly-ordered face-on structure of upper-deposited active layer is developed with low paracrystalline disorder, resulting in reasonably high response speed of the PM-OPD.