Using SSRL Beam Lines 11-3 and 10-1, a team of researchers including SSRL scientists Mike Toney and Jan Lüning (now at Université Pierre et Marie Curie), and Stanford University researchers, graduate students, Quan Yuan and Mingle Tang, postdoc Stefan Mannsfeld and Prof. Zhenan Bao, have determined the precise arrangement of molecules within a thin film sample of an organic semiconductor, a step that could soon help scientists better design these materials. The results appear in the March 19, 2008 issue of the Journal of the American Chemical Society.

Although well-understood, traditional silicon semiconductors are costly to manufacture, making large arrays of efficient solar arrays, for example, expensive. Organic semiconductors represent a potential source of inexpensive electronics that may one day be used to make solar cells, LCD displays and electronic paper.

Using Near Edge X-ray Absorption Fine Structure (NEXAFS) and Grazing Incidence X-ray Diffraction, the team examined thin-film samples of the organic, or "plastic," semiconductor material called thiotetracene, which was first reported by Prof. Zhenan Bao's group. Results obtained using the two techniques to determine the molecular arrangement of the semiconductor gives researchers a better understanding of how the molecular structure of the material relates to its electronic properties, paving the way for greater control over manufacturing such materials.

Thin film structure of tetraceno[2,3-b]thiophene characterized by grazing incidence X-ray scattering and near-edge X-ray absorption fine structure analysis, Q. Yuan, S.C.B. Mannsfeld, M.L. Tang, M.F. Toney, J. Lüning, Z. Bao, J. Am. Chem. Soc. 130, 3502 (2008)

High-performance organic semiconductors: Asymmetric linear acenes containing sulphur, M. L. Tang, T. Okamoto, Z. Bao, J. Am. Chem. Soc. 128, 16002 (2006)

To learn more about this research see the full scientific highlight at:
http://www-ssrl.slac.stanford.edu/research/highlights_archive/OTFT.html