Abstract
We study the operation of polymer light-emitting electrochemical cells (LECs) by combining scanning Kelvin probe microscopy with in situ imaging of the electroluminescence and photoluminescence on planar LECs. By combining these techniques on the same device in the same apparatus we directly map the relationship between the spatial distribution of electroluminescence and the local potential profile across the device. We find that the electroluminescence is always associated with a region of potential drop in LECs made with poly[2-methoxy-5-(3',7'-dimethyl-octyloxy)-p-phenylenevinylene] (MDMO-PPV), poly(ethylene oxide)(PEO), and potassium trifluoromethanesulfonate. Nevertheless, depending on the electrode metal used, we also find significant potential drops at or near the electrode/organic interfaces. We study the effects of using different electrodes and show that both the electroluminescence and potential profiles are strongly dependent on the electrode work function for thin junctions operated at low potentials. These results indicate injection barriers can affect the operation of LECs even in the presence of doping.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.