Almost all organic polymers are electrical insulators. Conductive polymers have a conjugated backbone of alternating single and double bonds that makes them semiconductors or even highly conductive (see chemistry Nobel prize for year 2000). Study of conductive polymers often includes small-length oligomers with well-defined numbers of monomer units.

In some cases, light emission is observed when a voltage is applied to a thin layer of a conductive organic polymer film. It has led to the development of flat panel displays using OLEDs, solar panels and optical amplifiers.

Conductivity in conjugated polymers can be increased by photoconductivity, oxidizing or reducing the polymer with a "dopant" (though unlike typical dopants, large amounts are used, on the order of 1:4 to 1:2 dopants per monomer unit). This increase in conductivity can also be accomplished in a field effect transistor (organic FET or OFET).