A reversible electrical memory switching and its microscopic mechanism in amorphous (NCTA)₂Ni(DMIT)₂ thin films

A reversible and reproducible bistable electrical memory switching phenomenon was observed in an asymmetrical sandwich structure with coherent electrodeposited amorphous thin films between Al and indium tin oxide electrodes based on a new type of molecular semiconductor (NCTA)₂Ni(DMIT)₂. It can be achieved between a high-impedance OFF state and a low-impedance ON state simply by changing the polarity of an applied electric field across the device. The electrical memory switching process is described in detail, and a plausible microscopic switching mechanism is proposed based on the formation and deformation of mixed-valence semiconductor through electric field-induced solid-state redox reaction resulting from a negative fractional charge withdrawing and injecting process.