{ital In situ} studies of morphology, strain, and growth modes of a molecular organic thin film

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.3046· OSTI ID:528095

Fenter, P ^[1]; Schreiber, F ^[2]; Zhou, L ^[3]; Eisenberger, P ^[4]; Forrest, S R ^[4]

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1. Princeton Materials Institute and Department of Physics, Princeton University, Princeton, New Jersey 08540 (United States)
2. Princeton Materials Institute and Department of Chemistry, Princeton University, Princeton, New Jersey 08540 (United States)
3. Department of Physics, Princeton University, Princeton, New Jersey 08540 (United States)
4. Princeton Materials Institute, Princeton University, Princeton, New Jersey 08540 (United States)

We use grazing incidence x-ray scattering to study the molecular structure and morphology of thin ({lt}70 ML) crystalline films of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on Au(111) surfaces as a function of film thickness, substrate temperature, and growth rate. Although the first two PTCDA monolayers grow in a layer-by-layer fashion, the film evolution beyond the second monolayer depends strongly upon the growth conditions resulting in low-temperature [i.e., nonequilibrium (NEQ)] and high-temperature [equilibrium (EQ)] growth regimes. In the NEQ regime, the films roughen monotonically with increasing film thickness, but retain a well-defined film thickness. Furthermore, we find that these films have a lattice strain which is independent of film thickness. In the EQ regime, the film acquires a three-dimensional morphology for thicknesses {gt}2 ML, and the lattice strain decreases rapidly with increasing thickness. We also show that the transition between the NEQ and EQ regimes is sharp and depends upon the balance between the growth rate and substrate temperature. These results suggest that the PTCDA/Au(111) system is thermodynamically described by incomplete wetting, and that strain and kinetics play an important role in determining molecular organic film characteristics. {copyright} {ital 1997} {ital The American Physical Society}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 528095
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 6 Vol. 56; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
FABRICATION
GROWTH
MORPHOLOGY
ORGANIC COMPOUNDS
STRAINS
STRESSES
THICKNESS
THIN FILMS
VAPOR DEPOSITED COATINGS
X RADIATION