ABSTRACT
This chapter discusses the electrical and optical properties of polymers having band gap energy (E g) of 1.8 eV or lower and optically transparent in their conducting state. The factors affecting the E g of polymer are discussed in detail with the characterization techniques used to determine E g. Low energy gap polymers (LEGPs) are primarily categorized into five groups, and several examples are cited herein for a better understanding of the structure–property relationship. Some problems related to the processability of LEGPs are mentioned, and approaches to improve the processability are discussed with examples from the literature. This chapter does not cover the synthesis of monomers and polymers or the fundamentals of optoelectronic devices as they are discussed in the previous chapters of this book.
