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Title: Asymmetric grain distribution in phthalocyanine thin films

Abstract

Many electronic and optical properties of organic thin films depend on the precise morphology of grains. Iron phthalocyanine thin films are grown on sapphire substrates at different temperatures to study the effect of grain growth kinematics and to experimentally quantify the grain size distribution in organic thin films. The grain size is measured with an atomic force microscope and the data is processed and analyzed with well-known image segmentation algorithms. For relevant statistics, over 3000 grains are evaluated for each sample. The data show pronounced asymmetric grain growth with increasing deposition temperature from almost spherical grains at room temperature to elongated needlelike shapes at 260 deg. C. The average size along the major axis increases from 35 to 200 nm and along the minor axis from 25 to 90 nm. The distribution is almost symmetric at low-deposition temperatures, but becomes lognormal at higher temperatures. Strikingly, the major axis and minor axis of the elliptically shaped grains have different distributions at all temperatures due to the planar asymmetry of the molecule.

Authors:
; ;  [1]
  1. Department of Physics and Astronomy, California State University-Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840 (United States)
Publication Date:
OSTI Identifier:
21294465
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 80; Journal Issue: 17; Other Information: DOI: 10.1103/PhysRevB.80.174118; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALGORITHMS; ASYMMETRY; ATOMIC FORCE MICROSCOPY; DISTRIBUTION; ELECTRICAL PROPERTIES; GRAIN GROWTH; GRAIN SIZE; IRON; MOLECULAR BEAM EPITAXY; OPTICAL PROPERTIES; ORGANIC SEMICONDUCTORS; PHTHALOCYANINES; ROUGHNESS; SAPPHIRE; SPHERICAL CONFIGURATION; SUBSTRATES; SURFACES; SYMMETRY; TEMPERATURE RANGE 0273-0400 K; THIN FILMS

Citation Formats

Gentry, K Paul, Gredig, Thomas, Schuller, Ivan K, and Department of Physics and Astronomy, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093. Asymmetric grain distribution in phthalocyanine thin films. United States: N. p., 2009. Web. doi:10.1103/PHYSREVB.80.174118.
Gentry, K Paul, Gredig, Thomas, Schuller, Ivan K, & Department of Physics and Astronomy, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093. Asymmetric grain distribution in phthalocyanine thin films. United States. https://doi.org/10.1103/PHYSREVB.80.174118
Gentry, K Paul, Gredig, Thomas, Schuller, Ivan K, and Department of Physics and Astronomy, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093. 2009. "Asymmetric grain distribution in phthalocyanine thin films". United States. https://doi.org/10.1103/PHYSREVB.80.174118.
@article{osti_21294465,
title = {Asymmetric grain distribution in phthalocyanine thin films},
author = {Gentry, K Paul and Gredig, Thomas and Schuller, Ivan K and Department of Physics and Astronomy, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093},
abstractNote = {Many electronic and optical properties of organic thin films depend on the precise morphology of grains. Iron phthalocyanine thin films are grown on sapphire substrates at different temperatures to study the effect of grain growth kinematics and to experimentally quantify the grain size distribution in organic thin films. The grain size is measured with an atomic force microscope and the data is processed and analyzed with well-known image segmentation algorithms. For relevant statistics, over 3000 grains are evaluated for each sample. The data show pronounced asymmetric grain growth with increasing deposition temperature from almost spherical grains at room temperature to elongated needlelike shapes at 260 deg. C. The average size along the major axis increases from 35 to 200 nm and along the minor axis from 25 to 90 nm. The distribution is almost symmetric at low-deposition temperatures, but becomes lognormal at higher temperatures. Strikingly, the major axis and minor axis of the elliptically shaped grains have different distributions at all temperatures due to the planar asymmetry of the molecule.},
doi = {10.1103/PHYSREVB.80.174118},
url = {https://www.osti.gov/biblio/21294465}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 17,
volume = 80,
place = {United States},
year = {Sun Nov 01 00:00:00 EDT 2009},
month = {Sun Nov 01 00:00:00 EDT 2009}
}