Project title: Modelling the relationship between processing, structure and properties in conjugated polymers

Supervisors: Anne Guilbert and Jenny Nelson

Project description:

Organic electronic materials are an important class of next-generation materials: exhibiting great flexibility in behaviour and offering less resource intensive manufacture than traditional semiconductors. We focus primarily on conjugated polymers for applications to Organic Photovoltaics (OPV), for which the final microstructure plays a key role in the performance of the device.  The microstructure of the active layers is strongly dependent on the chemical structure of the component materials and process routes used, and typically the highest performing structures are metastable arrangements. As a result, the structures of practical films and the behaviour of the resulting devices can be highly variable. Modelling structure is equally challenging because of the huge conformational phase space of conjugated polymer films. We focus on challenges of bridging length and time scales in simulations of polymer dynamics to start to unravel relationships between the processing and the final structure (and ultimately the performance). Initial work focuses on polyfluorene, where experimental studies have revealed the conditions in which a known conformer is formed in solution1 before progressing to more complex blends of organic materials.

Perevedentsev, Aleksandr, et al. "Solution‐crystallization and related phenomena in 9, 9‐dialkyl‐fluorene polymers. I. Crystalline polymer‐solvent compound formation for poly (9, 9‐dioctylfluorene)." Journal of Polymer Science Part B: Polymer Physics 53.21 (2015): 1481-1491.