3.3. Thin films or bulk samples
Self-assemble morphologies with nanoscale architectures in thin film of conjugated block copolymer are of current interest for device application, such as light-emitting diodes, photodiodes, memory, solar cell, and thin film transistors, etc. The exciton diffusion length is estimated to be around 10 nm before charge separation. Thus, the control on the nanoscale morphology within this scale is a key to enhance the optoelectronic device efficiency. In general, film structures have been prepared from a well-dispersed copolymer in a good solvent or solution-formed micelle in a selective solvent. Here we summarize the key factors that control the morphology of the thin film or bulk states of rod–coil block copolymers and discuss their corresponding device applications.