Silver Nanofilament Formation Dynamics in a Polymer‐Ionic Liquid Thin Film by Direct Write
Abstract
Silver nanofilament formation dynamics are reported for an ionic liquid (IL)‐filled solid polymer electrolyte prepared by a direct‐write process using a conductive atomic force microscope (C‐AFM). Filaments are electrochemically formed at hundreds of xy locations on a ≈40 nm thick polymer electrolyte, polyethylene glycol diacrylate (PEGDA)/[BMIM]PF6. Although the formation time generally decreases with increasing bias from 0.7 to 3.0 V, an unexpected non‐monotonic maximum is observed ≈2.0 V. At voltages approaching this region of inverted kinetics, IL electric double layers (EDLs) become detectable; thus, the increased nanofilament formation time can be attributed to electric field screening, which hinders silver electromigration and deposition. Scanning electron microscopy confirms that nanofilaments formed in this inverted region have significantly more lateral and diffuse features. Time‐dependent formation currents reveal two types of nanofilament growth dynamics: abrupt, where the resistance decreases sharply over as little as a few ms, and gradual where it decreases more slowly over hundreds of ms. Whether the resistance change is abrupt or gradual depends on the extent to which the EDL screens the electric field. Tuning the formation time and growth dynamics using an IL opens the range of accessible resistance states, which is useful for neuromorphic applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 28, 2019
- Source ID
- 10.1002/adfm.201907950
Entities
People
- Abigale E. Gray
- Christopher E Wilmer
- David B Go
- Garrison M Crouch
- Ke Xu
- Kutay Berk Sezginel
- Paul Bohn
- Susan K Fullerton-Shirey
- Zhongmou Chao
Organizations
- Defense Advanced Research Projects Agency
- National Aeronautics and Space Administration
- PPG Industries
- University of Notre Dame
- University of Pittsburgh