Proceedings of MATSUS Spring 2024 Conference (MATSUS24)
DOI: https://doi.org/10.29363/nanoge.matsus.2024.469
Publication date: 18th December 2023
Electrochemical random access memory (ECRAM) and organic electrochemical transistors (OECT) are gaining significant attention due to the unique properties introduced via the mobile ions. Despite the progress in device fabrication, there is very little in terms of device models.[1, 2] Here, we will describe results obtained using a 2D semiconductor device model that incorporates ions and reactions in a self-consistent manner.
For example, although OECTs electrolytes contain both cations and anions, it is common to consider only the primary ion (as a cation in a normally-off p-type transistor). We simulate normally-on and normally-off transistors showing that the normally-on is highly affected by the counter ions (anions) and field-screening at the contacts.
Inorganic ECRAM transistor devices have a structure similar to OECT, where the memory (ion retention) is provided by the diffusion's very high electric field activation. Comparing measured multi-level potentiation [3] to detailed device simulation, we reveal the role of electrolyte polarisation. We also show that sublinear potentiation response can be explained by an electrochemical reaction similar to that of lithium plating in batteries. Namely, electrochemical reactions must be considered when dealing with electrochemical devices.
This research was supported by the Ministry of Innovation, Science and Technology Israel, the M-ERANET grant PHANTASTIC Call 2021. Sapir Bitton is a fellow of the Ariane de Rothschild Women’s Doctoral Program.