This thesis describes an investigation into a wide range of potential materials for organic photovoltaic (PV) devices. Chapter 1 provides a general introduction relating to donor -acceptor systems and conjugated polymers with photovoltaic applications. Chapter 2 describes the design, synthesis and characterisation of new organic super-acceptors based on an NDI core. An investigation of their optical and redox properties is described. Chapter 3 describes the synthesis of new flavin-functionalised dithienylpyrrole systems. In addition, preliminary polymerisation studies are described, together with a study of their chemical and physical properties. Chapter 4 describes the synthesis and characterisation of new ferrocene and NDI functionalised polymers by ATRP and RAFT techniques. Chapter 5 describes the synthesis of new bis-acceptor systems based on NDI and TCAQ and a brief study their chemical and physical properties. Chapter 6 describes the synthesis of conjug-ated polymers featuring NDI units. Chapter 7 describes the synthesis and characterisation of novel substituted metal phthalocyanines featuring NDI units. Chapter 8 provides the experimental details and characterisation of all the compounds prepared in this thesis. Finally, chapter 9 provides the appendices and additional information
