Proceedings of 6th International Conference on Hybrid and Organic Photovoltaics (HOPV14)
Publication date: 1st March 2014
Due to its ballistic charge transport and high electron mobility reaching 10 000 cm2·V−1·s−1 at room temperature, graphene has been seen as one of the most exciting new materials for electronic devices. We present a study of the crystallizaton of highly regioregular poly-3-hexylthiophene (P3HT) on a single layer large area graphene sheet, and we measure its charge transport in the direction perpendicular to the film. The crystalline structure of the films was characterized by 2D grazing incidence X-rays synchrotron diffraction (2D GIXD).
Conductivity measurements showed that the film deposited on graphene resulted in at least 2 times increase in charge transport in the vertical direction compared to a similar film deposited on silicon. This result correlates with an enhanced vertical π–π stacking and higher degree of interconnectivity between crystallites. Raman and UV–vis spectroscopy also revealed a small increase in correlation length and in chain planarity on graphene. These results suggest that graphene could help improve charge transport and efficiency of organic and hybrid photovoltaics.