Abstract
As discussed in the previous chapters, the performance of organic thin film transistors (OTFTs) is strongly dependent on the microstructure of the semiconducting active layer [1–3]. For bottom gated OTFTs, the majority of the current flows within the first few monolayers at the dielectric/semiconductor interface; thus understanding and controlling the growth and nucleation of the semiconductor at this interface is crucial for device optimization [1–3]. The vast majority of the work on the thin film formation of pentacene, one of the highest mobility, and the most widely studied organic semiconductor, was investigated on silicon dioxide (SiO2) [4–9]. While SiO2 is a common (though less so than OTS treated SiO2) dielectric for evaluating organic semiconductors, for future commercial device applications including flexible low cost electronics, the dielectric will be an organic or polymeric material [1, 10–14]. Fundamental understanding and control of pentacene growth on organic surfaces is therefore crucial. As aforementioned, the most common organic surface used for OTFTs is a methyl terminated one wherein the SiO2 is treated with an alkylsilane monolayer like octadecylsilane (OTS) [15–18]. Treating the SiO2 with OTS reduces the surface energy, changes the chemical nature of the surface from polar to non-polar, and from inorganic to organic. OTS modification of SiO2 has also been shown to change organic semiconductor morphology and reduce interfacial hydroxyl groups which are known to be trap states. Most papers reported an increase in OTFT performance (mobility, and on/off) after treatment with OTS [1, 19, 20]. As was discussed in detail in Chap. 2, the molecular order and density of the underlying OTS monolayer was determined to be a critical factor that affects device performance of pentacene OTFTs [18, 21]. Despite the fact OTS treated SiO2 is the most common dielectric surface, there have been few quantitative studies on organic semiconductor growth on OTS modified SiO2.
Keywords
- Atomic Force Microscopy
- Organic Semiconductor
- Nucleation Density
- Organic Thin Film Transistor
- Stable Island
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsReferences
Bao Z, Locklin J (2007) Organic Field Effect Transistors. CRC Press Taylor and Francis Group, Boca Raton
Dinelli F. et al. (2004) Spatially correlated charge transport in organic thin film transistors. Phys Rev Lett 92:116802
Dodabalapur A, Torsi L, Katz HE (1995) Organic transistors—2-dimensional transport and improved electrical characteristics. Science 268:270–271
Brinkmann M, Pratontep S, Contal C (2006) Correlated and non-correlated growth kinetics of pentacene in the sub-monolayer regime. Surf Sci 600:4712–4716
Gundlach DJ, Lin YY, Jackson TN, Nelson SF, Schlom DG (1997) Pentacene organic thin-film transistors—Molecular ordering and mobility. IEEE Electron Dev Lett 18:87–89
Heringdorf F, Reuter MC, Tromp RM (2001) Growth dynamics of pentacene thin films. Nature 412:517–520
Kelley TW, Muyres DV, Baude PF, Smith TP, Jones TD. (2003) High performance organic thin film transistors. Organic and Polymeric Materials and Devices. Symposium (Mater. Res. Soc. Symposium Proceedings Vol.771), 169–179|xiii + 409
Mannsfeld SCB, Virkar A, Reese C, Toney MF, Bao ZN (2009) Precise structure of pentacene monolayers on amorphous silicon oxide and relation to charge transport. Adv Mater 21, 2294–2298
Northrup JE, Tiago ML, Louie SG (2002) Surface energetics and growth of pentacene. Phys Rev B (Condensed Matter and Materials Physics) 66, 121404–121407
Choudhary D, Clancy P, Bowler DR (2005) Adsorption of pentacene on a silicon surface. Surf Sci 578:20–26
Dimitrakopoulos CD, Malenfant PRL (2002) Organic thin film transistors for large area electronics. Adv Mater 14, 99–117
Klauk H, Zschieschang U, Pflaum J, Halik M (2007) Ultralow-power organic complementary circuits. Nature 445:745–748
Knipp D, Street RA, Volkel A, Ho J (2003) Pentacene thin film transistors on inorganic dielectrics: Morphology, structural properties, and electronic transport. J Appl Phys 93:347–355
Knipp D, Street RA, Volkel AR (2003) Morphology and electronic transport of polycrystalline pentacene thin-film transistors. Appl Phys Lett 82:3907–3909
Facchetti, A. et al. (2000) Tuning the semiconducting properties of sexithiophene by alpha,omega-substitution—alpha,omega-diperfluorohexylsexithiophene: The first n-type sexithiophene for thin-film transistors. Angew Chem Int Ed 39, 4547–4551
Halik M et al (2004) Low-voltage organic transistors with an amorphous molecular gate dielectric. Nature 431:963–966
Klauk H et al (2002) High-mobility polymer gate dielectric pentacene thin film transistors. J Appl Phys 92:5259–5263
Lee HS et al (2008) Effect of the phase states of self-assembled monolayers on pentacene growth and thin-film transistor characteristics. J Am Chem Soc 130:10556–10564
Chua LL et al (2005) General observation of n-type field-effect behaviour in organic semiconductors. Nature 434:194–199
Yang HC et al (2005) Conducting AFM and 2D GIXD studies on pentacene thin films. J Am Chem Soc 127:11542–11543
Virkar A et al (2009) The role of OTS density on pentacene and C-60 nucleation, thin film growth, and transistor performance. Adv Funct Mater 19:1962–1970
Ito Y et al (2009) Crystalline ultrasmooth self-assembled monolayers of alkylsilanes for organic field-effect transistors. J Am Chem Soc 131:9396–9404
Virkar A, Ling MM, Locklin J, Bao Z (2008) Oligothiophene based organic semiconductors with cross-linkable benzophenone moieties. Synth Met 158:958–963
Park YD, Lim JA, Lee HS, Cho K (2007) Interface engineering in organic transistors. Mater Today 10:46–54
Verlaak S, Steudel S, Heremans P, Janssen D, Deleuze MS (2003) Nucleation of organic semiconductors on inert substrates. Phys Rev B 68:195409
Locklin J, Bao ZN (2006) Effect of morphology on organic thin film transistor sensors. Anal Bioanal Chem 384:336–342
Roberts ME et al (2008) Water-stable organic transistors and their application in chemical and biological sensors. Proc Natl Acad Sci USA 105:12134–12139
Roberts ME, Sokolov AN, Bao ZN (2009) Material and device considerations for organic thin-film transistor sensors. J Mater Chem 19:3351–3363
Kobayashi S et al (2004) Control of carrier density by self-assembled monolayers in organic field-effect transistors. Nat Mater 3:317–322
Lee SH, Saito N, Takai O (2007) The importance of precursor molecules symmetry in the formation of self-assembled monolayers. Jpn J Appl Phys 1 Regul Pap Brief Commun Rev Pap 46, 1118–1123
Porter MD, Bright TB, Allara DL, Chidsey CED (1987) Spontaneously organized molecular assemblies.4. structural characterization of normal-alkyl thiol monolayers on gold by optical ellipsometry, infrared-spectroscopy, and electrochemistry. J Am Chem Soc 109:3559–3568
Markov I (2003) Crystal growth for beginners: fundamentals of nucleation, crystal growth and epitaxy 2nd edn. World Scientific, New Jersey
Venables JA, Spiller GDT, Hanbucken M (1984) Nucleation and growth of thin-films. Rep Prog Phys 47:399–459
Venables JA (1973) Rate equation approaches to thin-film nucleation kinetics. Philos Mag 27:697–738
Pratontep S, Brinkmann M, Nuesch F, Zuppiroli L (2004) Correlated growth in ultrathin pentacene films on silicon oxide: effect of deposition rate. Phys Rev B 69:165201
Pratontep S, Nuesch F, Zuppiroli L, Brinkmann M (2005) Comparison between nucleation of pentacene monolayer islands on polymeric and inorganic substrates. Phys Rev B 72(8):85211
Ohring M (2001) The material science of thin films, 2nd edn. Academic Press, Orlando
Yoshikawa G. et al. (2007) Spontaneous aggregation of pentacene molecules and its influence on field effect mobility. Appl Phys Lett 90:251906
Lim SC et al (2005) Surface-treatment effects on organic thin-film transistors. Synth Met 148:75–79
Damm W, Frontera A, TiradoRives J, Jorgensen WL (1997) OPLS all-atom force field for carbohydrates. J Comput Chem 18:1955–1970
Chwang AB, Frisbie CD (2000) Field effect transport measurements on single grains of sexithiophene: role of the contacts. J Phys Chem B 104:12202–12209
Huang J, Sun J, Katz HE (2008) Monolayer-dimensional 5,5’-Bis(4-hexylphenyl)-2,2’-bithiophene transistors and chemically responsive heterostructures. Adv Mater 20, 2567–2572
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2012 Springer Science+Business Media, LLC
About this chapter
Cite this chapter
Virkar, A. (2012). The Nucleation, Surface Energetics and Stability of Pentacene Thin Films on Crystalline and Amorphous Octadecylsilane Surface. In: Investigating the Nucleation, Growth, and Energy Levels of Organic Semiconductors for High Performance Plastic Electronics. Springer Theses. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-9704-3_3
Download citation
DOI: https://doi.org/10.1007/978-1-4419-9704-3_3
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4419-9703-6
Online ISBN: 978-1-4419-9704-3
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)