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


Published in:
Physical Review B (Condensed Matter and Materials Physics), 72, 8, 85211
Year:
2005
Publisher:
APS through AIP
Keywords:
Note:
Inst. Charles Sadron, Strasbourg, France
Copyright 2005, IEE
8602909
0163-1829
polymer substrates
pentacene monolayer islands growth
saturated nucleation density
inorganic substrates
submonolayer regime
sapphire substrates
poly(methyl-metacrylate)
scaling laws
deposition parameter
deposition rate
substrate temperature
Arrhenius law
critical nucleus size
activation energy
dielectric material
molecule-substrate interactions
SiO2
Al2O3
Other identifiers:
Laboratories:




 Record created 2007-04-03, last modified 2018-03-17


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