ABSTRACT
Electrical and optical properties of CPs generally depend on their redox states, and also on the extent of doping. Upon doping, CPs convert to their conducting form and a redshift in the absorption maximum is observed resulting in a different color. This forms the basis of electrochromic devices (Figure 7.2). For example, poly(thiophene)s are yellow-orange in their neutral state and blue in their conducting state. Colors of conjugated polymers are, in general, complementary to the visible wavelengths absorbed.
