title: Assembly and organization of poly(3-hexylthiophene) brushes and their potential use as novel anode buffer layers for organic photovoltaics.
abstract: Buffer layers that control electrochemical reactions and physical interactions at electrode/film interfaces are key components of an organic photovoltaic cell. Here the structure and properties of layers of semi-rigid poly(3-hexylthiophene) (P3HT) chains tethered at a surface are investigated, and these functional systems are applied in an organic photovoltaic device. Areal density of P3HT chains is readily tuned through the choice of polymer molecular weight and annealing conditions, and insights from optical absorption spectroscopy and semiempirical quantum calculation methods suggest that tethering causes intrachain defects that affect co-facial π-stacking of brush chains. Because of their ability to modify oxide surfaces, P3HT brushes are utilized as an anode buffer layer in a P3HT-PCBM (phenyl-C₆₁-butyric acid methyl ester) bulk heterojunction device. Current-voltage characterization shows a significant enhancement in short circuit current, suggesting the potential of these novel nanostructured buffer layers to replace the PEDOT:PSS buffer layer typically applied in traditional P3HT-PCBM solar cells.
authors: Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors: José
authors: J
authors: Alonzo
authors: W Michael
authors: WM
authors: Kochemba
authors: Deanna L
authors: DL
authors: Pickel
authors: Muruganathan
authors: M
authors: Ramanathan
authors: Zhenzhong
authors: Z
authors: Sun
authors: Dawen
authors: D
authors: Li
authors: Jihua
authors: J
authors: Chen
authors: Bobby G
authors: BG
authors: Sumpter
authors: William T
authors: WT
authors: Heller
authors: S Michael
authors: SM
authors: Kilbey
mesh_terms: D004566:Electrodes; D010087:Oxides / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D012993:Solar Energy; D013499:Surface Properties; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D010087:Oxides; D011137:Polystyrenes; D013876:Thiophenes; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); C507295:poly(3-hexylthiophene)