title: Scaling and Exponent Equalities in Island Nucleation: Novel Results and Application to Organic Films.
abstract: It is known in thin-film deposition that the density of nucleated clustersNvaries with the deposition rateFas a power law,N ∼ Fα. The exponent α is a function of the critical nucleus sizeiin a way that changes with the aggregation limiting process. We extend here the derivation of the analytical capture-zone distribution functionPβ(s) =aß·sβ·exp(-bβs2) of Pimpinelli and Einstein to generic aggregation-limiting processes. We show that the parameter β is generally related to the critical nucleus sizeiand to the exponent α by the equality α·β =i, in the case of compact islands. This remarkable result allows one to measureiwith noa prioriknowledge of the actual aggregation mechanism. We apply this equality to measuring the critical nucleus size for pentacene deposition on mica. This system shows a crossover from diffusion-limited to attachment-limited aggregation with increasing deposition rates.
authors.affiliation: Rice Quantum Institute, Rice University , Houston, Texas 77005, United States.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pimpinelli
authors.affiliation: Institute of Solid State Physics, Graz University of Technology , 8010 Graz, Austria.
authors.forename: Levent
authors.initials: L
authors.lastname: Tumbek
authors.affiliation: Institute of Solid State Physics, Graz University of Technology , 8010 Graz, Austria.
authors.forename: Adolf
authors.initials: A
authors.lastname: Winkler