Electronic structure of polymers

Abstract The object of this review is to critically evaluate recently published work directed toward development of comprehensive microscopic models for the electronic structures of organic polymers. Since organic polymers now include an enormous range of structures and properties, the scope of a review in this field must be curtailed if reasonable depth of discussion is to be achieved. We limit our attention in this review to polymers comprised of a carbon chain which exhibits various bonding arrangements, depending upon the type of molecular group that is covalently bonded to the carbon chain atoms. Specifically, we discuss the conjugated chain polymers, polyene and polydiacetylene, in conjunction with saturated chain polymers that vary in complexity from polyethylene to polymers characterized by a polyethlenic chain containing large pendant groups. These present an interesting progression of properties from nearly metallic behavior (polyene) to severe carrier localization caused by diagonal disorder (pendant group polymers). The description of the electronic structures of these latter materials requires the introduction of concepts more familiar in the fields of electrochemistry and physical chemistry than solid state physics as necessary supplements to the theoretical constructs traditionally found applicable to rigid periodic arrays of atoms.