A stack for a bistable microelectronic switch. A porphyrin compound and a
conductive polymer are sandwiched between two electrodes. The device
exhibits a switching behavior at a certain voltage and can be used in
arrays to form a memory device. When a first voltage is applied between
the electrodes, the resistance across the two electrodes is very high,
and when a increased voltage is applied, the resistance is generally two
orders of magnitude lower. Copper phthalocyanine or 5, 10, 15,
20-tetrakis(4-methoxyphenyl)-21H, 23H-porphine cobalt(II) can be used as
the bistable compound, and poly-(3,4-ethylenedioxythiophene) and
poly-(styrenesulphonic acid) can be used as the conductive polymer.