Large Gain-Bandwidth product photomultiplication-type organic photodetectors introducing quantum dot layer
발표자
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초록
내용
We demonstrate a high performance photomultiplication-type organic photodetector (PM-OPD) based on a bulk heterojunction (BHJ) of donor and acceptor materials and a core-shell quantum dot (QD) interlayer. The PM-OPD shows high specific detectivity, external quantum efficiency (EQE), and fast response time compared to other PM-OPDs, resulting in large EQE-bandwidth product (~105 Hz). This notable performance is enabled by the novel device structure (ITO/ZnO/donor-acceptor BHJ/QD/Ag), where fast charge trapping of photo-generated electrons at the QD interlayer induced fast charge injection from the electrodes. This is distinguished from conventional PM-OPDs, which usually suffer from slow response time due to the relatively long charge accumulation time required for the charge injection from the electrodes. This work offers a new insight on the design of device structure for fast-response and high-performing PM-OPDs and provides comprehensive understanding of underlying device physics.