Abstract

Organic semiconductors such as small molecules and conjugated polymers have been demonstrated as the active material in light-emitting diodes, transistors and photovoltaic cells. While innovation in new organic semiconductor materials and solution-processing techniques continues to improve the performance of organic devices, further research is required to gain crucial insights into the fundamental relationships between structure and optoelectronic properties and inform future design strategies. To achieve this goal, two main challenges must be overcome:

1. establishing an accurate and robust control over the microstructure of organic thin films
2. developing techniques to characterise the thin-film properties at a sufficiently high resolution

In this talk, Dr Kim will discuss the key advances in our understanding in these two main challenging areas. She will introduce a simple solution-deposition technique to print organic semiconductors in thin films with controlled structure and morphology. She will also demonstrate Raman spectroscopy as one of the most valuable structural probes for organic semiconductor thin films, addressing the application of non-resonant, resonant and polarized Raman spectroscopy to the characterisation of reaction, composition, crystallinity and orientation of molecules [1-6]. Based on these studies, she will finally discuss the impact of organic semiconductor microstructures on optoelectronic and charge transport properties and hence device performance.

Presenter

Ji-Seon Kim is Reader in Physics at the Imperial College London. She has held Visiting Professorship at KAIST, South Korea (2009-2013) and EPSRC Advanced Research Fellowship (2004-2010). She obtained a PhD in Physics in 2000 from the University of Cambridge and was a Post-Doctoral Research Associate in Cambridge. She conducts research on the basic science and technology of molecular electronic materials and devices, in particular to establish the correlation between organic nanostructures and the performance of associated devices and hence to develop molecular (plastic) electronics for next generation technology (>90 papers, h-index of 32, ~4700 total citations). She has been lead or co-investigator on a number of research projects targeting the control and characterization of organic structures for various optoelectronic devices including solar cells, displays & lighting and transistors (>£10 million research funds secured). She is also conducting scientific research as a technical consultant for Cambridge Display Technology Ltd.

References and Publications

1. James et al., ACS Nano 7(9) (2013) 7983-7991
2. Wood et al., J. Chem. Phys. 139(6) (2013) 064901
3. Li et al., Nature Communications 4 (2013) 2227
4. Tsoi et al., ACS Nano, 6(11), (2012), 9646-9656
5. Tsoi et al., J. Am. Chem. Soc., 133, (2011), 9834-9843
6. James et al., ACS Nano 5 (12), (2011), 9824-9835