High-Resolution Near-Field Optical Investigation of Crystalline Domains in Oligomeric PQT-12 Thin Films
Autor: | Markus Breusing, Thomas Fischer, Dieter Neher, Patrick Pingel, Sergei Kuehn, Joachim Stumpe, Thomas Elsaesser |
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Přispěvatelé: | Publica |
Rok vydání: | 2011 |
Předmět: |
Polarized light microscopy
Materials science Institut für Physik und Astronomie Condensed Matter Physics Dichroic glass Electronic Optical and Magnetic Materials law.invention Biomaterials Organic semiconductor Crystallography Optical microscope law Chemical physics Electrochemistry Nanometre Crystallite Thin film Layer (electronics) |
Zdroj: | Advanced Functional Materials. 21:860-868 |
ISSN: | 1616-301X |
DOI: | 10.1002/adfm.201001978 |
Popis: | The structure and morphology on different length scales dictate both the electrical and optical properties of organic semiconductor thin fi lms. Using a combination of spectroscopic methods, including scanning near-fi eld optical microscopy, we study the domain structure and packing quality of highly crystalline thin fi lms of oligomeric PQT-12 with 100 nanometer spatial resolution. The pronounced optical anisotropy of these layers measured by polarized light microscopy facilitates the identifi cation of regions with uniform molecular orientation. We fithat a hierarchical order on three different length scales exists in these layers, made up of distinct well-ordered dichroic areas at the ten-micrometer-scale, which are sub-divided into domains with different molecular in-plane orientation. These serve as a template for the formation of smaller needle-like crystallites at the layer surface. A high degree of crystalline order is believed to be the cause of the rather high fi eld-effect mobility of these layers of 10 − 3 cm 2 V − 1 s − 1 , whereas it is limited by the presence of domain boundaries at macroscopic distances. |
Databáze: | OpenAIRE |
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