Multibit memory using self-assembly of mixed ferrocene/porphyrin monolayers on silicon

An alternative strategy for achieving multi-bit functionality, which uses mixed self-assembled monolayers of a benzyl alcohol-tethered ferrocene (Fc-BzOH) and a benzyl alcohol-tethered porphyrin (Por-BzOH) on silicon surfaces to achieve a four-state (2-bit) memory element, is presented. The four states include the neutral state and three distinct cationic states obtained upon oxidation of Fc-BzOH (monopositive) and Por-BzOH (monopositive, dipositive) molecules. Conventional cyclic voltammetry, capacitance, and conductance methods have been used to characterize the mixed monolayer.