How Ligands Affect Resistive Switching in Solution-Processed HfO2 Nanoparticle Assemblies

Abstract

Advancement of resistive random access memory (ReRAM) requires fully understanding the various complex, defect-mediated transport mechanisms to further improve performance. Although thin-film oxide materials have been extensively studied, the switching properties of nanoparticle assemblies remain underexplored due to difficulties in fabricating ordered structures. Here, we employ a simple flow coating method for the facile deposition of highly ordered HfO₂ nanoparticle nanoribbon assemblies. The resistive switching character of nanoribbons was determined to correlate directly with the organic capping layer length of their constituting HfO₂ nanoparticles, using oleic acid, dodecanoic acid, and undecenoic acid as model nanoparticle ligands. Through a systematic comparison of the forming process, operating set/reset voltages, and resistance states, we demonstrate a tunable resistive switching response by varying the ligand type, thus providing a base correlation for solution-processed ReRAM device fabrication.

Keywords: hafnium oxide; ligands; nanoparticles; resistive switching; solution-processed.