Nucleation of organic semiconductors on inert substrates

We have adapted the microscopic theory of nucleation for the epitaxial growth of inorganic materials to the nucleation of organic small molecules on an inert substrate like the gate dielectric of an organic thin-film transistor. The parameters required to explore the model were calculated with the standard MM3 force field and also include experimentally determined vapor pressure data, as well as film growth data. Sufficient agreement is found between the experimentally determined equilibrium crystal shape and heats of sublimation on the one hand and the calculated parameters on the other hand. The growth of pentacene, tetracene, and perylene on inert substrates has been studied in terms of this theory, especially focusing on the two-dimensional (2D) to 3D nucleation transition. It is demonstrated that 3D nucleation leads to ill-connected grains, while 2D nucleated grains form continuous films suitable for charge transport. The analysis of this transition allows for the experimental determination of the molecule-substrate interactions for a given molecule on a given surface. It was found that the deposition conditions for 2D growth shift to less favorable substrate temperatures and deposition rates as the difference between interlayer interactions and molecule-substrate interactions increase and the intralayer interactions decrease. Moreover, those interactions affect the nucleation rate and therefore the ultimate 2D grain size that can be obtained.

[1]  R. B. Campbell,et al.  The crystal structure of hexacene, and a revision of the crystallographic data for tetracene , 1962 .

[2]  Norman L. Allinger,et al.  Molecular mechanics. The MM3 force field for hydrocarbons. 2. Vibrational frequencies and thermodynamics , 1989 .

[3]  R. Zamboni,et al.  SCALING BEHAVIOR OF ANISOTROPIC ORGANIC THIN FILMS GROWN IN HIGH VACUUM , 1997 .

[4]  A. Camerman,et al.  The crystal and molecular structure of perylene , 1964, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[5]  C. G. D. Kruif,et al.  Enthalpies of sublimation and vapour pressures of 11 polycyclic hydrocarbons , 1980 .

[6]  H. Inokuchi,et al.  Heats of Sublimation of Polycyclic Aromatic Hydrocarbons and Their Molecular Packings , 1967 .

[7]  R. M. Tromp,et al.  Growth dynamics of pentacene thin films , 2001, Nature.

[8]  R. Zamboni,et al.  Growth of conjugated oligomer thin films studied by atomic-force microscopy. , 1995, Physical review. B, Condensed matter.

[9]  H. Klauk,et al.  Organic thin-film transistors for organic light-emitting flat-panel display backplanes , 1998 .

[10]  R. Haddon,et al.  Enhanced Physical Properties in a Pentacene Polymorph. , 2001, Angewandte Chemie.

[11]  R. A. Laudise,et al.  Vapor pressures of organic semiconductors:: α-hexathiophene and α-quaterthiophene , 1998 .

[12]  H. Inokuchi,et al.  Electrical Conductivity of Organic Semiconductors , 1961 .

[13]  Thomas N. Jackson,et al.  Thin-film transistors based on well-ordered thermally evaporated naphthacene films , 2002 .

[14]  N. Karl,et al.  Electron and Hole Mobilities in High Purity Anthracene Single Crystals , 2001 .

[15]  Francesco Zerbetto,et al.  How do benzylic amide [2]catenane rings rotate? , 1999 .

[16]  I. Markov,et al.  Mechanisms of epitaxial growth , 1987 .

[17]  Norman L. Allinger,et al.  Heats of formation of organic molecules. 2. The basis for calculations using either ab initio or molecular mechanics methods. Alcohols and ethers , 1992 .

[18]  Michael S. Deleuze,et al.  Can Benzylic Amide [2]Catenane Rings Rotate on Graphite? , 2000 .

[19]  Michael A. Haase,et al.  Pentacene-based radio-frequency identification circuitry , 2003 .

[20]  T. Jackson,et al.  Pentacene organic thin-film transistors-molecular ordering and mobility , 1997, IEEE Electron Device Letters.

[21]  E. Venuti,et al.  Inherent structures of crystalline pentacene , 2003 .

[22]  K. Peter C. Vollhardt,et al.  On the Nature of Nonplanarity in the [N]Phenylenes , 1999 .

[23]  T. Jackson,et al.  Stacked pentacene layer organic thin-film transistors with improved characteristics , 1997, IEEE Electron Device Letters.

[24]  M. Deleuze,et al.  Molecular packing of oligomer chains of poly(p-phenylene vinylene) , 2001 .

[25]  Norman L. Allinger,et al.  Molecular mechanics. The MM3 force field for hydrocarbons. 3. The van der Waals' potentials and crystal data for aliphatic and aromatic hydrocarbons , 1989 .

[26]  Gautam R. Desiraju,et al.  Crystal structures of polynuclear aromatic hydrocarbons. Classification, rationalization and prediction from molecular structure , 1989 .

[27]  James S. Chickos,et al.  Enthalpies of Sublimation of Organic and Organometallic Compounds. 1910–2001 , 2002 .

[28]  N. L. Allinger,et al.  Conformational analysis—129: Heats of formation and thermodynamic parameters for hydrocarbons, calculated by the molecular mechanics method including the effects of molecular vibrations, , 1979 .

[29]  T. Klapwijk,et al.  Morphology identification of the thin film phases of vacuum evaporated pentacene on SIO2 substrates , 1999 .

[30]  W. Warta,et al.  Ultrapure, high mobility organic photoconductors , 1985 .

[31]  M. Ohring.  The Materials Science of Thin Films , 1991 .

[32]  S. Louie,et al.  Surface energetics and growth of pentacene , 2002 .

[33]  M. Deleuze,et al.  High level theoretical study of the structure and rotational barriers of trans-stilbene , 2003 .

[34]  M. Wuttig,et al.  Modifying the growth of organic thin films by a self-assembled monolayer , 2003 .