Impact of dopant geometry on memristive properties of oriented layers of conjugated macromolecular nanowires

Abstract

Memristive materials are of great interest due to their potential in modern electronics and computing technologies. While most studies focus on inorganic systems, organic and polymer-based alternatives are also emerging. This work presents surface-grafted polymer brushes with conjugated polyacetylene chains as an efficient memristive system and explores their tunability through doping with inorganic salts. The brushes were synthesized in a two-step process, starting with polymethacrylate brushes obtained via surface-initiated photoiniferter-mediated radical polymerization. Characterization using AFM, XPS, and FTIR confirmed the presence of tetrahedral [FeCl₄]⁻ and linear [CuCl₂]⁻ counterions incorporated into the conjugated chains. The doping process, performed for 10 and 60 minutes, shows pinched hysteresis loop. The influence of doping and dopant geometry on electrical, memristive, structural properties, and film thickness was analyzed. Additionally, experimental findings were supported by DFT modeling, providing deeper insights into the behavior of the system.