Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8034249 | Thin Solid Films | 2015 | 7 Pages |
Abstract
α,Ï-Functionalised oligothiophenes are promising materials for organic field effect transistors due to their high degree of molecular ordering, crystallinity and Ï-Ï stacking. We employ several complementary microspectroscopic probes to investigate the formation of thermally evaporated films of 5,5â´-bis(N-acetamido-2-ethyl)-2,2â²:5â²,2â³:5â³,2â´quaterthiophene on inert substrates. These films were found to grow in a mixed fashion, featuring layer-by-layer domains with thicknesses of several monolayers and needle-shaped three-dimensional crystals. Detailed analysis of atomic force microscopy (AFM) and photoluminescence microscopy reveals the micro- and nanomorphology of the films. Linear dichroism in the near edge x-ray absorption fine structure and polarisation-dependent laser excitation corroborate the findings of AFM, i.e., upright standing molecules in the multilayer regime. The shape of the 3-dimensional crystallites and multilayer domains indicates strongly anisotropic growth favoured by the herringbone-arrangement of the thiophene moieties and additional stabilisation by hydrogen bonding of the acetamide end groups.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Nina Zeilmann, Benedikt Rösner, Andreas Späth, Ute Schmidt, Rainer H. Fink,