Solvents Effects on Film Morphologies and Memory Behavior of a Perylenediimide-Containing Pendent Polymer

Graphical Remember this? A sandwich-structured device of indium tin oxide (ITO)/polymer/aluminum exhibited different electrical behavior and threshold voltages in different solvent mixtures of different ratios (see figure). This study suggests that polymeric memory behavior can be efficiently adjusted through the use of mixed solvents. The large polydispersity index of functional pendant polymers has hindered their application in semiconductors. Herein, a novel pendant polymer with perylenediimide (PDI) in the side chains was successfully synthesized through ring-opening metathesis polymerization (ROMP) with a very low polydispersity index. The synthesized polymers were spin-coated on indium tin oxide (ITO) substrate by using a mixture of 1,2-dichlorobenzene ( o -DCB) and methanol (MeOH) solvents. The surface morphologies and intermolecular π–π stacking of the fabricated film could be adjusted through tuning of the ratio of o -DCB and MeOH, and thus, the sandwich-structured device of ITO/polymer/aluminum exhibited different electrical behavior. The threshold voltages of the devices decreased as the MeOH content was increased from 0 to 30 % (v/v); however, the device changed from being unrewritable to rewritable if the MeOH content was increased to 40 %; a probable mechanism for this process is discussed. It is hoped that this new idea of synthesizing narrow polydispersity index pendant polymers, and the fabrication of high-quality films through the use of a mixture of solvents could allow high-performance memory devices to be prepared in the future.