Influence of the Electron Deficient Co-Monomer on the Optoelectronic Properties and Photovoltaic Performance of Dithienogermole-based Co-Polymers - Yau, CP; Fei, Z; Ashraf, RS; Shahid, M; Watkins, SE; Pattanasattayavong, P; Anthopoulos, TD; Gregoriou, VG; Chochos, CL; Heeney, M (ADVANCED FUNCTIONAL MATERIALS, 2014)