Development of organic optoelectronic devices have gained great deal of attention in recent years due to unique advantages over their inorganic counterpart such as easy processability and flexibility. The demand for clean and renewable energy have amplified development of organic polymer for commercialization. The focus of development has gone into conjugated organic polymers and turning band gap. Donoracceptor (D-A) methodology have been the most effective strategy in conceptualizing these developments. This thesis consists of four parts: 1) design, syntheses and characterization of diketopyrrolopyrrole (DPP)- based polymers bearing thermal cleavable moiety used for multilayer device structure; 2) introduction of a stronger acceptor, diazapentalene (DAP), in polymer to achieve coverage of longer wavelength and study of multilayer device for photodetection; 3) development of cross-linkable polymer for use as p-type interface layer; 4) modification of benzothiadiazole (BT) acceptor to study electrochromic activity in the near-infrared region.