| 초록 |
A fast-response photomultiplication-type organic photodiode (PM-OPD) is demonstrated. The PM-OPD uses a bulk heterojunction (BHJ) of donor and acceptor materials and a core-shell quantum dot (QD) interlayer. The PM-OPD shows large specific detectivity, external quantum efficiency (EQE), and bandwidth compared to other PM-OPDs showing large EQE-bandwidth product of 105 Hz which is an important figure-of merit of photodetectors. This performance is enabled by the novel device structure (ITO/ZnO/donor-acceptor BHJ/QD/Ag), where fast charge trapping dynamics of the QD interlayer results in fast response of the PM-OPD. In addition, the respons speed of the proposed device can be modulated by controlling charge trapping dynamics of the QDs. As a result, a fast-response of 109 kHz, which is the largest among the values reported, is obtained. This work offers new insights on device structure for high-performing PM-OPDs and provides comprehensive understanding of underlying device physics. |
