Cells By Self-assembly
Work has examined using supramolecular chemistry, using donor and acceptor molecules that assemble upon spin casting and heating. Most supramolecular assemblies employ small molecules. Donor and acceptor domains in a tubular structure appear ideal for organic solar cells.
Diblock polymers containing fullerene yield stable organic solar cells upon thermal annealing. Solar cells with pre-designed morphologies have been built when appropriate supramolecular interactions are introduced.
Progress on BCPs containing polythiophene derivatives yield solar cells that assemble into well defined networks. This system exhibits a PCE of 2.04%. Hydrogen bonding guides the morphology.
Device efficiency based on co-polymer approaches have yet to cross the 2% barrier, whereas bulk-heterojunction devices exhibit efficiencies >7% in single junction configurations.
Fullerene-grafted rod-coil block copolymers have been used to study the domain organization. The active layer morphology of polymer organic solar cells affects device performance. Device efficiency correlates with the distribution of donor and acceptors. Electron and hole mobility within the active layer usually correlates with efficiencies. Vertical segregation within the active layer is important to the device performance. Solvent evaporation rate, donor and acceptor miscibilities and additives also influence device characteristics. Overall, the influence of donor and acceptor interactions on morphology is poorly understood. Supramolecular approaches to organic solar cells, while in its infancy, provides understanding about the macromolecular forces that drive domain separation.
Read more about this topic: Polymer Solar Cell
Famous quotes containing the word cells:
“The twelve Cells for Incorrigibles ... are also carved out of the solid rock hill. On the walls of one of the cells human “liberty” is clearly inscribed, with the “liberty” in significant quotation marks.”
—Administration in the State of Ariz, U.S. public relief program (1935-1943)