Complex morphologies in thin films of symmetric diblock copolymers as stable and unstable phases

Using real-space, parallel self-consistent field (SCF) calculations with high accuracy, we performed a detailed study on the self-assembled morphology of symmetric diblock copolymer thin films between two homogeneous surfaces. Even in this simplest case of block copolymers under nano-confinement, rich phase behavior is found with various complex morphologies having both parallel and perpendicular lamellar orientations. In addition to their interesting structures, the formation mechanisms and stability of these complex morphologies are also clearly revealed by the detailed free-energy data obtained from the SCF calculations.