Reduced Dark Current Density in Organic Photodiode with Conjugated Polymers Bearing Fluorinated Moiety
발표자
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초록
내용
A low dark current density (Jd) is critical for enhancing the performance of organic photodiodes (OPDs), which is evaluated by device parameters such as the signal-to-noise ratio, specific detectivity (D*), and linear dynamic range. However, the design rules for conjugated polymers to reduce Jd in OPDs are rarely accessible. In this study, we present a strategy to obtain low Jd in OPDs from a material point of view, by investigating the optoelectric properties of OPDs based on donor-acceptor (D-A) type conjugated copolymers. Systematic analyses based on structural characterization of the active thin-film layers and the sub-gap density of states (DOS) measured using the OPDs and organic field-effect transistors revealed that the fluorination of the electron donor unit in the D-A type conjugated polymer is an effective way to reduce the Jd of OPDs by suppressing trap DOS in the blended active layer.