title: Remarkable order of a high-performance polymer.
abstract: We directly image the rich nanoscale organization of the high performance, n-type polymer poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (P(NDI2OD-T2)) using a combination of high-resolution transmission electron microscopy and scanning transmission electron microscopy. We demonstrate that it is possible to spatially resolve "face-on" lamella through the 2.4 nm alkyl stacking distance corresponding to the (100) reflection. The lamella locally transition between ordered and disordered states over a length scale on the order of 10 nm; however, the polymer backbones retain long-range correlations over length-scales approaching a micrometer. Moreover, we frequently observe overlapping structure implying a number of layers may exist throughout the thickness of the film (~20 nm). The results provide a simple picture, a highly ordered lamella nanostructure over nearly the entire film and ordered domains with overlapping layers providing additional interconnectivity, which unifies prior seemingly contradictory conclusions surrounding this remarkable, high-mobility material.
authors: Department of Physics, Broida Hall, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
authors: Christopher J
authors: CJ
authors: Takacs
authors: Neil D
authors: ND
authors: Treat
authors: Stephan
authors: S
authors: Krämer
authors: Zhihua
authors: Z
authors: Chen
authors: Antonio
authors: A
authors: Facchetti
authors: Michael L
authors: ML
authors: Chabinyc
authors: Alan J
authors: AJ
authors: Heeger