A bistable electrical device that is convertible between a low resistance
state and a high resistance state. The device includes at least one layer
of organic low conductivity material that is sandwiched between two
electrodes. A buffer layer is located between the organic layer and at
least one of the electrodes. The buffer layer includes particles in the
form of flakes or dots of a low conducting material or insulating
material that are present in a sufficient amount to only partially cover
the electrode surface. The presence of the buffer layer controls metal
migration into the organic layer when voltage pulses are applied between
the electrodes to convert the device back and forth between the low and
high resistance states.