The key challenge is to establish the synthesis-structure-property relationship that covers polymer chemistry/physics, charge transport mechanism, and optical theories. Despite great effort to the development of material, the long-wave IR optical properties of CPs are largely unexplored, especially when considering the properties at various states from various synthesis and processing conditions with complicated structure-dependent charge transport kinetics. In addition, the vast majority of CP-based IR electrochromic devices are limited to those lying in the insulating side of the Anderson-Mott transition, limiting the tuning mechanism to transmissive and lossy dielectric .