Organic nonvolatile resistive switching memory based on molecularly entrapped fullerene derivative within a diblock copolymer nanostructure

摘要

Organic nonvolatile resistive switching memory is developed via selective incorporation of fullerene derivatives, 6,6-phenyl-C61 butyric acid methyl ester (PCBM), into the nanostructure of self-assembled poly(styrene-b-methyl methacrylate) (PS10-b-PMMA130) diblock copolymer. PS_(10)-b-PMMA_(130) diblock copolymer provides a spatially ordered nanotemplate with a 10-nm PS nanosphere domain surrounded by a PMMA matrix. Spin casting of the blend solution of PS10-b-PMMA 130 and PCBM spontaneously forms smooth films without PCBM aggregation in which PCBM molecules are incorporated within a PS nanosphere domain of PS_(10)-b-PMMA_(130) nanostructure by preferential intermixing propensity of PCBM and PS. Based on the well-defined PS_(10)-b-PMMA_(130)/PCBM nanostructure, resistive random access memory (ReRAM) exhibits significantly improved bipolar-switching behavior with stable and reproducible properties at low operating voltages (RESET at 1.3 V and SET at -1.5 V) under ambient conditions. Finally, flexible memory devices are achieved using a nanostructured PS_(10)-b-PMMA_(130)/PCBM composite in which no significant degradation of electrical properties is observed before and after bending. Flexible nonvolatile resistive memory devices using self-assembled block copolymer/PCBM nanocomposites are introduced. The spherical phase of PS10-b-PMMA130 finely controls the segregation of PCBM and improves the performance of memory devices. The memory devices show bipolar characteristics with stable and reproducible performance.