MBE growth of para-hexaphenyl on GaAs(001)-2×4

• Published in: Surface science Vol. 418; no. 1; pp. 256 - 266
• Main Authors: Müller, B, Kuhlmann, T, Lischka, K, Schwer, H, Resel, R, Leising, G
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 27-11-1998; Amsterdam Elsevier Science; New York, NY
• Subjects: Atomic force microscopy; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Gallium arsenide; Hexaphenyl; Molecular beam epitaxy; Nucleation; Physics; Structure and morphology; thickness; Surface morphology; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Molecular beam epitaxy; Atomic force microscopy; Hexaphenyl; Nucleation; Gallium arsenide; Surface morphology; Thin films; Temperature dependence; Deposition rate; XRD; Experimental study; Microstructure; Island structure; Organic compounds; Film growth
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00720-1

The morphology of
para-hexaphenyl (PHP) grown on GaAs(001) by molecular beam epitaxy has been studied using atomic force microscopy (AFM). For elevated substrate temperatures between 90 and 170°C and a deposition rate of 0.7
Å
s
−1, it was found that hexaphenyl on GaAs(001)-2×4 forms well-defined, three-dimensional islands of a rectangular shape oriented in 〈100〉. Their constant width indicates that PHP is epitaxially grown as a coherently strained organic material. The island density shows the Arrhenius behavior resulting in activation barrier of (0.90±0.04)
eV. The normalized island size distributions closely resemble that of a critical island size of one. On the basis of the AFM measurements, X-ray diffraction data, and geometrical considerations, we developed a structural model for PHP grown on GaAs(001).