An
electric field activated molecular
system, preferably bi-stable, configured within an
electric field generated by a pair of electrodes is provided for use, e.g., as electronic ink or other visual displays. The molecular
system has an
electric field induced
band gap change that occurs via a change (reversible or irreversible) of the extent of the
electron conjugation via chemical bonding change to change the
band gap, wherein in a first state, there is substantial conjugation throughout the molecular
system, resulting in a relatively smaller
band gap, and wherein in a second state, the substantial conjugation is destroyed, resulting in a relatively larger band gap. The changing of substantial conjugation may be accomplished in one of the following ways: (1)
charge separation or recombination accompanied by increasing or decreasing
electron localization in the molecule; or (2) change of substantial conjugation via
charge separation or recombination and pi-
bond breaking or making. A primary
advantage of the molecular system is improved contrast. Because the colorant of the present invention is molecular and thus effectively monoplanar, there should be no backside reflection or excessive scattering from the colorant. A second
advantage of the present invention is improved resolution. Finally, each molecule of the present invention will latch to stabilize one or the other of its color states.