A multistate memory cell based on electrochromic metallo-organic assemblies

The search for new materials to fabricate electronic devices mainly targets composites of metals, metal oxides, organic molecules, and polymers. We demonstrate here the fabrication and operation of a multilevel-per-bit metallo-organic memory cell (MOMC). This conceptually new memory cell has dual functionality. Information can be written and stored electrochemically and read out both electrochemically and optically. An electrochemical readout will reset the device to its ground state (read-while-write), whereas an optical readout can be continuous. The use of a nanoscale trilayer of electrochromically active ruthenium, iron, and osmium polypyridyl complexes resulted in up to four distinct states that can be addressed by applying different potentials. The information stored in the MOMC was used as input to an integrated circuit (IC), and it was visualized using light-emitting diodes (LEDs). These findings show the potential of metallo-organic materials to design hybrid ICs.