Book excerpt: Functional organic and organometallic polymers and materials have gained much attention as versatile materials for energy interconversions and optoelectronic/photonic applications, including electrical energy generation in photovoltaic cells and light generation in organic light-emitting diodes, as they offer a low cost, light weight and simple option for device fabrication.Molecular Design and Applications of Photofunctional Polymers and Materials, presents a critical perspective of the current field, with emphasis on fundamental concepts and current applications in optoelectronics, electronics and nanotechnology. The book also covers photochemically degradable polymers, electrochromic and photochromic materials, biosensing and bioimaging materials, and low- and high-refractive index materials.With contributions from leading experts in the field, this timely book will provide a valuable contribution to the community enabling new synthetic methods to be developed to produce new materials with specific functional roles.