In this study, diketopyrrolopyrrole-based copolymer namly, Poly{3,6-dithien-2-yl-2,5-di(2-decyltetradecanyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-5’,5’’-diyl-alt-tryphenyamine} (PDTDPP-alt-TPA) is synthesized and fully characterized by GPC, NMR, UV-vis absorption, and cyclic voltammetry. To access the profile in the electric applications, not only OFETs is tested but also bulk heterojunction solar cell is evaluated.