Novel molecular device based on electrostatic interactions in organic polymers

This work reports a study on the relationship between the zero-field carrier mobility and the potential profile in a polymer in the presence of space charge. Physically, space charge residing in a subgroup and in the backbone of the polymer will form a dipolar layer and modifies the potential profile. Any barriers so created will affect charge flow along the backbone as well as into and out of the subgroups, which is the normal pathway to inter-chain current transport. In this work, we examined the effect on the potential profiles when different subgroups were attached to the backbone and compared the results to data for OC₁C₁₀-PPV reported in the literature. Our calculations suggested a strong correlation between the type of subgroup and the potential minimum created. This will affect the value of the zero-field mobility. Modulation of the voltage applied to a subgroup should allow manipulation of the potential profile and hence the charge flow along the backbone, forming a basis for designing molecular devices based on electrostatic interactions as proposed by Tour et al.