The memory cell or the memory array formed of such memory cells has different molecular or polymeric layers forming an electrochemical redox pair. A matrix acting as proton donors or acceptors is provided in the two different molecular or polymeric layers. If a corresponding voltage is applied between mutually crossing upper and lower interconnects, one layer of their molecules emits electrons to the interconnect. As a result the molecules are oxidized. At the same time, electrons flow from the other interconnect into the molecules of the other polymer layer. As a result the molecules of that layer are reduced. Charge transport is balanced by proton flow, so that the oxidation state of the two layers is stabilized. If the voltage polarity is reversed, the memory cell is rewritten to the initial form. The memory array is suitable where the number of read-outs significantly exceeds the number of write operations, for example in smart cards.