Over the last decade, halogenated semiconducting polymers have attracted considerable interest due to their outstanding optoelectronic properties. Thus, most today's OPV benchmark organic semiconductors are halogenated materials, either electron donor polymers or non-fullerene acceptor (NFA) small molecules. However, the nature and position of the substituted halogen atoms in halogenated semiconducting polymers impact, through self-assembly modification, on their optoelectronic properties in a way which is 2 difficult to predict. Yet, the solid-state self-assembling of this materials has been shown to be a key parameter towards high charge transport properties and photovoltaic efficiencies. In this context, there is still a need to develop analytical methods that will enable an atomicscale structural characterization of these materials as function of the halogenation. In this manuscript, we explore the solid-state nuclear magnetic resonance (NMR) under magic angle spinning (MAS) as a tool to investigate the local structure and supramolecular organization of a series of conjugated polymers, specially designed for this study. Through a comprehensive study using complementary techniques including MAS-NMR, small and wideangle X-ray scattering (SWAXS) and molecular modelling investigations, we have definitely succeeded in determining the molecular conformation of these polymers in relation to their chemical composition.