Structure/Property Relations in Conjugated Polythiophenes for Photonics Applications
Edward R. Van Keuren and Robert C. White
Pseudo-one-dimensional conjugated polymers are an interesting class of materials which have been developed for a number of photonics applications. A wide range of variation in the electronic and optical properties can be achieved through changes in the polymer structures. The underlying photophysics results from delocalized electrons along the main polymer chain and the nature of localization is controlled in principle by electronic structural changes in conjunction with conformational changes by, e.g., chemical substitution, doping and interchain interactions. We review these basic ideas and present results of a comprehensive effort developing polythiophenes, a well-studied member of the class of one class of pseudo-one-dimensional conjugated polymers. The value of polythiophenes in photonic applications is based on what is perhaps the most important structure-property relationship in conjugated polymers, which is the chemical stability and processibility as a function of the molecular structure.