@article{ScholzSauerWiessneretal.2013, author = {Scholz, M. and Sauer, C. and Wiessner, M. and Nguyen, N. and Scholl, A. and Reinert, F.}, title = {Structure formation in organic thin films observed in real time by energy dispersive near-edge x-ray absorption fine-structure spectroscopy}, series = {New Journal of Physics}, volume = {15}, journal = {New Journal of Physics}, number = {083052}, doi = {10.1088/1367-2630/15/8/083052}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129749}, year = {2013}, abstract = {We study the structure formation of 1,4,5,8-naphthalenetetracarboxylicacid- dianhydride (NTCDA) multilayer films on Ag(111) surfaces by energy dispersive near-edge x-ray absorption fine-structure spectroscopy (NEXAFS) and photoelectron spectroscopy. The time resolution of seconds of the method allows us to identify several sub-processes, which occur during the post-growth three-dimensional structural ordering, as well as their characteristic time scales. After deposition at low temperature the NTCDA molecules are preferentially flat lying and the films exhibit no long-range order. Upon annealing the molecules flip into an upright orientation followed by an aggregation in a transient phase which exists for several minutes. Finally, threedimensional islands are established with bulk-crystalline structure involving substantial mass transport on the surface and morphological roughening. By applying the Kolmogorov-Johnson-Mehl-Avrami model the activation energies of the temperature-driven sub-processes can be derived from the time evolution of the NEXAFS signal.}, language = {en} }