We propose to study the thermodynamic structures and quench dynamics of a novel block copolymer:fullerene nanocomposite towards the design of optimized charge transport pathways in polymer solar cells. This experiment will quantify the effects of blend composition on the equilibrium nanostructures formed as well as measuring the kinetic rates of the relevant equilibration processes, namely block copolymer self-assembly and fullerene crystallisation. By constraining the fullerene crystals within an ordered block copolymer suprastructure, we will molecularly engineer the size and shape of charge transport pathways. Time-resolved SANS spectra will be quantitatively fitted to determine the size and composition of crystals within the suprastructure. Combined phase behaviour data and kinetic rate constants will enable us to target processing conditions for more efficienct devices.