Comparison between nucleation of pentacene monolayer islands on polymeric and inorganic substrates

We present a comparative study of the nucleation and growth of pentacene monolayer islands in the submonolayer regime onto inorganic substrates of SiO<sub>2</sub> and sapphire (Al<sub>2</sub>O<sub>3</sub>) and organic substrates of poly(methyl-metacrylate) (PMMA). We have determined the scaling laws that govern the saturated nucleation density per unit area N as a function of two essential deposition parameters: the deposition rate &kappa; and the substrate temperature T<sub>s</sub>. For all substrates, we found N&prop;&kappa;<sup>&delta;</sup>, with 0.8&les;&delta;&les;1.2, and the T<sub>s</sub> dependence of the nucleation density follows a typical activated Arrhenius law. Whereas a critical nucleus size of i=2 is obtained for all investigated substrates, the activation energy for nucleation depends significantly on the dielectric. The difference in activation energy of nucleation on PMMA and SiO<sub>2</sub> is due to different molecule-substrate interactions


Publié dans:
Physical Review B (Condensed Matter and Materials Physics), 72, 8, 85211
Année
2005
ISSN:
0163-1829
Mots-clefs:
Note:
Inst. Charles Sadron, Strasbourg, France
8602909
Autres identifiants:
Laboratoires:




 Notice créée le 2007-04-03, modifiée le 2020-07-30


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