Interfacial domain structure of polycrystalline semiconducting polymer films

Lead Research Organisation: University of Cambridge
Department Name: Physics


The objective of the proposed research is to use cutting-edge synchrotron-based techniques to answer fundamental questions regarding the operation of real-world organic electronic devices. Electronic devices based on organic (carbon-based) semiconductors are just beginning to enter the market place enabling a new generation of low-cost, flexible electronic displays and devices. Unlike traditional inorganic semiconductor materials such as Silicon, organic semiconductors have a highly complicated and often disordered film structure. Therefore to improve our understanding of the operation of these devices we need to fully characterise the structure of these films. Synchrotron-based microscopes are powerful tools that are ideally suited to this task that allow for the bulk and surface structure of materials to be probed with sub-micrometre resolution. Additionally, the use of lower energy soft X-rays with energies that match the molecular resonances in carbon-based materials allows for additional structural and chemical information to be extracted. The results of this research will help to enable next generation organic semiconductor materials and devices.


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McNeill C (2013) Soft X-ray characterisation of organic semiconductor films in J. Mater. Chem. C

Description The project was aimed at developing new tools for characterising the microstructure and domain structure of semiconducting polymer thin films to better understand at a microscopic level the structure-property relationships of these functional materials. It resulted in the development of a powerful new methodology for characterising polymer microstructure based on a combination of soft X-ray absorption/transmission, grazing incidence X-ray diffraction and optical spectroscopy.
Exploitation Route The technique and insight gained has primarily advanced the scientific understanding of structure-property relationships and the device physics of conjugated polymer semiconductors. It has not led directly to industrially exploitable technologies, but it is providing new experimental tools and important molecular design guidelines to chemical companies and materials developers to realize novel polymer semiconductor materials with improved electronic and optical properties. The technique is now widely used in the field for investigating the microstructure and structure-property relationships of polymer semiconductors. During the grant period Co-Investigator Dr. Chris McNeill was appointed to a Senior Lectureship at Monash University in Australia, where he is now leading an internationally widely recognized group on the structure-property relationships of organic semiconductors. Generally, the techniques of near-edge X-ray absorption fine structure (NEXAFS) and scanning transmission X-ray microscopy (STXM) that were extensively used in the project are now becoming standard techniques for the microstructure characterisation of organic semiconductors and are used by a growing number of international groups.
Sectors Electronics