Growth of pseudomorphic structures through organic epitaxy

Journal Article · Fri Dec 14 00:00:00 EST 2012 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4770001· OSTI ID:22099129

Kaviyil, Sreejith Embekkat; Sassella, Adele; Borghesi, Alessandro ^[1]; Campione, Marcello ^[2]; Genbo, Su; Youping, He ^[3]; Chenjia, Chen ^[4]

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1. Department of Materials Science, Universita degli Studi di Milano Bicocca, Via R. Cozzi 53, I-20125 Milan (Italy)
2. Department of Earth and Environmental Sciences, Universita degli Studi di Milano Bicocca, Piazza della Scienza 4, I-20126 Milan (Italy)
3. Fujian Institute of Research on the Structure of Matter, Chinese Academy of Science, Fuzhou 350002 (China)
4. Department of Physics, Peking University, Beijing 100871 (China)

The control of molecular orientation in thin solid film phases of organic semiconductors is a basic factor for the exploitation of their physical properties for optoelectronic devices. We compare structural and optical properties of thin films of the organic semiconductor {alpha}-quarterthiophene grown by molecular beam epitaxy on different organic substrates. We show how epitactic interactions, characteristic of the surface of organic crystals, can drive the orientation of the crystalline overlayer and the selection of specific polymorphs and new pseudomorphic phases. We identify a key role in this phenomenon played by the marked groove-like corrugations present in some organic crystal surfaces. Since different polymorphs possess rather different performance in terms of, e.g., charge carrier mobility, this strategy is demonstrated to allow for the growth of oriented phases with enhanced physical properties, while keeping the substrate at room temperature. These results provide useful guidelines for the design of technological substrates for organic epitaxy and they substantiate the adoption of an organic epitaxy approach for the fabrication of optoelectronic devices based on thin films of organic semiconductors.

• OSTI ID: 22099129
• Journal Information: Journal of Chemical Physics, Vol. 137, Issue 22; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARRIER MOBILITY
CHARGE CARRIERS
COMPARATIVE EVALUATIONS
CRYSTALS
FABRICATION
LAYERS
MOLECULAR BEAM EPITAXY
OPTICAL PROPERTIES
ORGANIC SEMICONDUCTORS
ORIENTATION
PERFORMANCE
SURFACES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
ULTRAVIOLET SPECTRA