Applied physics communications · 1983 · 172 citations · 0 references
Polymeric materials display an astounding range of electronic properties. There are polymeric superconductors, semiconductors, and even insulators whose resistivities are as high as those of fused quartz. Aside from the special high (or low) conductivity systems, the majority of polymers are rather poor conductors with electrical conductivities about eighteen orders of magnitude lower than those of metals. This disparity notwithstanding, there are some underlying similarities in the nature of these materials. Quite generally, the conduction bands are narrow, the interaction between the charge carriers and the random thermal oscillation is pronounced and often there are large amounts of disorder. All of the features tend to localize the electron states. We will discuss these ideas and develop the physics of these materials with strong localization tendencies, in a format which is general enough to include not only polymers but also, other types of organic or inorganic systems. Noncrystalline or amorphous silicon is an archetypical member of this family as well.