Thermally Stable Ternary Data-Storage Device Based on Twisted Anthraquinone Molecular Design

Three donor–acceptor and twisted anthraquinone azo molecules were synthesized, and the effects of conjugated backbones length, alkyl chains length, and the thermal annealing temperature on the memory characteristics were explored. The device based on <b>Azo-02</b>, which has longer conjugated backbone and alkyl chains, exhibited stable nonvolatile ternary memory behavior as the thermal annealing temperature increased, with basically the same switching threshold voltages and current ratios being ∼1:10^3.43:10^5.50. For the “counterpart” molecules (<b>Azo-01</b> and <b>Azo-03</b>) film, defects appeared or disordered, crystal packing formed as the thermal annealing temperature increased, and the corresponding devices exhibited no obvious conductance switching behaviors. The mechanism related to electrical switching properties and WORM (write-once-read-many-times) behaviors were elucidated through molecular simulation. The results demonstrated that the long-term thermally stable high-density data-storage devices can be fabricated by adjusting the structures of twisted molecules