POS5-0929
Backbone-Controlled Ion-Side Chain Accessibility in Conjugated Polymers for Organic Electrochemical Synaptic Transistors
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Byeongjun Jeon (Seoul National University of Science and Technology)
Co-Author(s)
Abstract
Stable nonvolatile memory is essential for organic neuromorphic semiconductors, where synaptic performance is strongly influenced by interactions between the conjugated polymer channel and mobile anions. Here, conjugated polymers with identical glycol side chains but different backbone structures were investigated to understand how backbone modulation affects ion accessibility and retention.
Devices based on the extended-backbone polymer exhibited enhanced nonvolatile characteristics, including a wider hysteresis window, stronger long-term potentiation, and improved memory retention. In situ UV–vis, TOF-SIMS, and GIWAXS analyses revealed that this improvement originates from enhanced anion doping, suppressed de-doping, and doping-induced structural reorganization in the side-chain-rich region.
To elucidate the molecular origin of this behavior, DFT calculations were performed using polymer–anion adsorption models. The optimized structures showed that TFSI anions preferentially interact with glycol side chains, which can form cage-like conformations around the anions. Four-chain models with two anions further demonstrated that the adsorption energy follows the same trend as the experimental device performance.
These results indicate that conjugated backbone design indirectly controls ion–side chain interactions by modulating side-chain spacing and accessibility, providing a molecular design strategy for improving nonvolatile synaptic behavior in organic electrochemical devices.
Devices based on the extended-backbone polymer exhibited enhanced nonvolatile characteristics, including a wider hysteresis window, stronger long-term potentiation, and improved memory retention. In situ UV–vis, TOF-SIMS, and GIWAXS analyses revealed that this improvement originates from enhanced anion doping, suppressed de-doping, and doping-induced structural reorganization in the side-chain-rich region.
To elucidate the molecular origin of this behavior, DFT calculations were performed using polymer–anion adsorption models. The optimized structures showed that TFSI anions preferentially interact with glycol side chains, which can form cage-like conformations around the anions. Four-chain models with two anions further demonstrated that the adsorption energy follows the same trend as the experimental device performance.
These results indicate that conjugated backbone design indirectly controls ion–side chain interactions by modulating side-chain spacing and accessibility, providing a molecular design strategy for improving nonvolatile synaptic behavior in organic electrochemical devices.
