Lecture: 'Understanding Charge Transport in Organic Field Effect Transistors'

The organic electronics research field has advanced tremendously in the last decades, already rendering semiconductors able to compete with their inorganic counterparts. However, the final blossoming of this field would probably come with the complete understanding of the charge transport mechanism in organic materials.

It is known that the performance of organic semiconductors is governed not only by the molecular structure but also by how molecules or polymer chains assemble in the solid state. Therefore, analyzing organic semiconductors from both a molecular and supramolecular point of view is highly desirable. For this end, Raman spectroscopy is a rapid, non-invasive technique able to gather information on molecular and supramolecular levels, thus being really useful in organic electronics.

In addition, it is well known that the largest contribution to charge transport occurs within the first few nanometers of the semiconductor near the dielectric interface. Thus, in order to analyze the charge transport processes, it is greatly desirable to characterize that buried interface. Surface Enhanced Raman spectroscopy (SERS) appears as an easy and straightforward technique to carry out this task and to provide useful information on molecular orientation at the device active layer.

In this seminar, some examples will be presented in which several various spectroscopic techniques, conventional Raman and SERS, supported by DFT quantum chemical calculations have been used to shed light on the mechanism of charge transport in organic field effect transistors (OFETs).

About the speaker

Rocio Ponce Ortiz is Associate Professor of Physical Chemistry at the University of Málaga. She received her BSc in Chemical Engineering and PhD in Chemistry at the same University in the field of Raman spectroscopy of organic semiconductors. Further research followed at Northwestern University in Evanston, IL, USA, on the organic electronics field. Her current research focuses on the study of organic materials with applications in electronics and photonics, combining physico-chemical analyses with device fabrication and characterization. She has coauthored 71 original publications and has an H-index of 32.

She has received several awards, being the most recent ones the award L´Oréal- UNESCO “For Women in Science” in 2014 and the award of the Spanish Royal Society of Chemistry to the most talented young people (under the age of 40) in 2015.