Redox-Gated Molecular Memory Devices Based on Dynamic Doping of Polythiophene

Wednesday, May 14, 2014: 08:00
Floridian Ballroom H, Lobby Level (Hilton Orlando Bonnet Creek)
R. L. McCreery (National Institute for Nanotechnology, University of Alberta), B. Das, R. Pillai (National Institute for Nanotechnology, Department of Chemistry, University of Alberta), N. Pekas (National Institute for Nanotechnology), and D. B. James (University of Alberta)
A solid state electrochemical cell resembling a field effect transistor will be described which can act as a nonvolatile memory element.  “Write” and “Erase” pulses cause oxidation of a polythiophene to its conducting form, while the conductance is monitored by a “read” circuit.  Raman and UV-Vis spectroelectrochemistry were used during device operation to investigate redox reactions which underlie memory operation.  Important electrochemical concepts which control device operation include activated electron transfer, ion motion, and extended conjugation.  In particular, internal ion transport creates ohmic potential losses which slow W/E operation, but can be significantly improved with higher mobility solid electrolytes. Applications seeking to augment existing silicon electronics with molecular components will be described.

Recent references:

(1)  Yan, H.; Bergren, A. J.; McCreery, R.; Della Rocca, M. L.; Martin, P.; Lafarge, P.; Lacroix, J. C.; Activationless charge transport across 4.5 to 22 nm in molecular electronic junctions; Proceedings of the National Academy of Sciences 2013, 110, 5326.

(2)  McCreery, R.; Yan, H.; Bergren, A. J.; A Critical Perspective on Molecular Electronic Junctions: There is Plenty of Room in the Middle; Phys. Chem. Chem. Phys. 2013, 15, 1065.

(3)  Sayed, S. Y.; Fereiro, J. A.; Yan, H.; McCreery, R. L.; Bergren, A. J.; Charge transport in molecular electronic junctions: Compression of the molecular tunnel barrier in the strong coupling regime; Proceedings of the National Academy of Sciences 2012, 109, 11498.

(4)  Kumar, R.; Pillai, R. G.; Pekas, N.; Wu, Y.; McCreery, R. L.; Spatially Resolved Raman Spectroelectrochemistry of Solid-State Polythiophene/Viologen Memory Devices; Journal of the American Chemical Society 2012, 134, 14869.