Characterization of ion movement in organic electronic devices
EMSL Project ID
42323
Abstract
An emerging advantage of organic semiconductors is their ability to conduct ions in applications such as light-emitting electrochemical cells, photovoltaics, actuators, and electrochromic devices, among others. This ability of organic materials to conduct both ionic and electronic currents in the solid state sets these materials apart from their inorganic counterparts, potentially enabling disruptive technologies not modeled after existing semiconductor devices, yet these benefits are under-utilized, in part because the fundamental electrochemical processes in these materials are not well characterized. In particular, evidence suggests that the profiles of ions and electrochemical doping in the polymer film during operation significantly impacts the performance and stability of the device. However, ion transport and electrochemical doping in the conjugated polymer films are not well understood. The primary objective of this proposal is to build a comprehensive picture of ion migration, ion profiles, and electrochemical activity in polymer-based devices. This will be achieved by directly profiling ion distributions in an operational LEC device before, during and after application of voltage, using Scanning Electron Microscopy (SEM), Electron Dispersive X-ray Spectroscopy (EDS), and Secondary Ion Mass Spectrometry (SIMS). These measurements will provide a detailed map of ions in the polymer film as well as compositional analysis of separate phases, and allow us to correlate this information with changes in device performance. These techniques will therefore provide crucial information relevant to a wide range of emerging technologies based on electrochemically active, or iontronic devices. Currently, we do not have access to SEM/EDS with the required sensitivity and resolution to obtain the necessary data. Further, Western Washington University does not have Secondary Ion Mass Spectrometry capabilities. Access to the facilities at EMSL will therefore be critical in carrying out the proposed research.
Project Details
Project type
Exploratory Research
Start Date
2011-02-01
End Date
2012-02-05
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Toshner SB, Z Zhu, IV Kosilkin, and JM Leger. 2012. "Characterization of Ion Profiles in Light-Emitting Electrochemical Cells by Secondary Ion Mass Spectrometry." ACS Applied Materials & Interfaces 4(3):1149-1153.