Phthalocyanine-Cored Star-Shaped Polystyrene for Nano Floating Gate in Nonvolatile Organic Transistor Memory Device

A novel non-volatile organic memory device is developed based on an organic field effect transistor (OFET) with a dielectric layer of a four-armed, star-shaped polymer featuring a copper phthalocyanine (CuPc) core. The CuPc core unit of the star-shaped polystyrene (CuPc-PS₄) self-assembles to form aggregates via π–π interactions, which are isolated and dispersed in the polymer thin film. The OFET memory device employing CuPc-PS₄ shows significant hole-trapping characteristics with a high memory ON/OFF current ratio of 10⁷, long retention ability of over 10⁴ s, and good endurance of more than 100 cycles, which is attributed to a flash-type memory. The novel polymer design with CuPc core assemblies inside the polymer matrix is a promising candidate for nano floating gates in non-volatile OFET memory.