3.3.4.3. Photovoltaics (PVs)
By combing the electron-donating conjugated rod block and electron-accepting coil block also rendered an opportunity to form thermodynamically optimized nano-structured films for photovoltaic applications. Generally, the exciton diffusion length is limited to approximately 10 nm. The resulting controlled segregation of rod–coil diblock copolymers with large donor–acceptor interface promotes exciton dissociation into free charge carriers. On the other hand, the donor and acceptor phase domain should be of this order to prevent the recombination of the photogenerated excitons. Active layers with organized nanodomains exhibited the higher photovoltaic efficiencies, indicating that molecular scale segregation had a significant effect on device performance (Fig. 32) [120]. Therefore, rod–coil block copolymers provide a versatile platform for realizing the control over nanoscale morphology to obtain acceptable efficiencies of solar cells.