Compositions – Electrically conductive or emissive compositions
Reexamination Certificate
2001-07-24
2003-07-01
Kopec, Mark (Department: 1751)
Compositions
Electrically conductive or emissive compositions
C528S377000
Reexamination Certificate
active
06585914
ABSTRACT:
BACKGROUND OF THE INVENTION
Thiophene chemistry and the chemical stability of the thiophene ring hold potential for use of thiophene materials in molecular-based electronics and photonics. In particular, &agr;&agr;′-conjugated thiophene oligomers (nTs) and polymers (polythiophenes-PTs) have attracted great interest as semiconducting elements in organic thin-film transistors (TFTs).
[1,2,]
To be useful in such devices and related structures, the
organic material must support a channel of holes or electrons (p- or n-type semiconductor, respectively) created by the gate electrode bias, which switches the device “on”. Furthermore, the charge mobility of the material must be sufficiently large to increase the source-drain on-conduction by many orders of magnitude over the “off” state. The density of the charge carrier in the channel is modulated by voltage applied at the gate electrode.
To date, the most noteworthy examples of this family of compounds are unsubstituted, &agr;,&ohgr;- and &bgr;,&bgr;′-dialkylsubstituted nT (n=4,6), and &bgr;-alkylsubstituted PT, where optimized carrier mobilities (0.1-0.6 cm
2
V
−1
s
−1
) and on/off ratios (>10
6
) approach those of amorphous silicon.
[1e,2a,c,e,3]
However, without exception, these systems facilitate hole injection and behave as p-type semiconductors, presumably because the thiophene electron-richness renders negative carriers susceptible to trapping by residual impurities such as oxygen
[4]
. Even so, increasing the number of thiophene units decreases dramatically environmental (air, light) stability and causes processing and purification difficulties.
Electron transporting (n-type) organic materials are relatively rare. However, developing/understanding new n-type materials would enable applications
[5]
such as bipolar transistors, p-n junction diodes, and complementary circuits as well as afford better fundamental understanding of charge transport in molecular solids. The major barrier to progress however, is that most n-type organics are either environmentally sensitive, have relatively low field mobilities, lack volatility for efficient film growth, and/or are difficult to synthesize.
[5e,6,7]
As indicated by the foregoing notations, these and other aspects of and teachings of the prior art can be found in the following:
[1] (a) G. Horowitz, F. Kouki, A. El Kassmi, P. Valat, V. Wintgens, F. Gamier,
Adv. Mater
. 1999, 11, 234. (b) F. Gamier, R. Hajaoui, A. El Kassmi, G. Horowitz, L. Laigre, W. Porzio, M. Armanini, F. Provasoli,
Chem. Mater
. 1998, 10, 3334. (c) X. C. Li, H. Sirringhaus, F. Gamier, A. B. Holmes, S. C. Moratti, N. Feeder, W. Clegg, S. J. Teat, R. H. Friend,
J. Am. Chem. Soc
. 1998, 120, 2206. (d) G. Horowitz, F. Kouki, F. Gamier,
Adv. Mater
. 1998, 10, 382. (e) L. Antolini, G. Horowitz, F. Kouki, F. Garnier,
Adv. Mater
. 1998. 10, 381. (f) G. Horowitz,
Adv. Mater
. 1998, 10, 365.
[2] (a) W. Li, H. E. Katz, A. J. Lovinger, J. G. Laquindanum,
Chem. Mater
. 1999, 11, 458. (b) H. E. Katz, J. G. Laquindanum, A. J. Lovinger,
Chem. Mater
. 1998, 10, 633. (c) J. G. Laquindanum, H. E. Katz, A. J. Lovinger,
J. Am. Chem. Soc
. 1998, 120, 664. (d) T. Siegrist, C. Kloc, R. A. Laudise, H. E. Katz, R. C. Haddon,
Adv. Mater
. 1998, 10, 379. (e) H. E. Katz,
J. Mater. Chem
. 1997, 7, 369. (f) A. Dodalabapur, L. Torsi, H. E. Katz,
Science
1995, 268, 270.
[3] (a) H. Sirringhaus, P. J. Brown, R. H. Friend, K. Bechgaard, B. M. W. Lengeveld-Voss, A. J. H. Spiering, R. A. J. Janssen, E. W. Meijer, P. Herving, D. M. de Leeuw,
Nature
1999, 401, 685. (b) G. Barbarella, M. Zambianchi, L. Antolini, P. Ostoja, P. Maccagnani, A. Bongini, E. A. Marseglia, E. Tedesco, G. Gigli, R. Cingolani,
J. Am. Chem. Soc
. 1999, 121, 8920. (c) J. H. Shon, C. Kloc, R. A. Laudise, B. Batlogg,
Appl. Phys. Lett
. 1998, 73, 3574.
[4
] Handbook of Heterocyclic Chemistry
; A. R. Katritzky Ed.; Pergamon Press: Oxford, 1983.
[5] (a) Y. Y. Lin, A. Dodabalapur, R. Sarpeshkar, Z. Bao, W. Li, K. Baldwin, V. R. Raju, H. E. Katz,
Appl. Phys. Lett
. 1999, 74, 2714. (b) G. Horowitz,
Adv. Mater
. 1998, 10, 365. (c) A. Dodalabapur, J. G. Laquindanum, H. E. Katz, Z. Bao,
Appl. Phys. Lett
1996, 69, 4227. (d) N. C. Greenham, S. C. Moratti, D. D. C. Bradley, R. H. Friend,
Nature
1993, 365, 628. (e) S. Sze,
Semiconductor Devices Physics and Technology
; Wiley: N.Y., 1985; p. 481.
[6] (a) C. P. Jarret, K. Pichler, R. Newbould, R. H. Friend,
Synth. Met
. 1996, 77,35. (b) R. C. Haddon,
J. Am. Chem. Soc
. 1996, 118, 3041. (c) G. Horowitz, F. Kouki, P. Spearman, D. Fichou, C. Nogues, X: Pan, F. Gamier,
Adv. Mater
. 1996, 8, 242. (d) J. G. Laquindanum, H. E. Katz, A. Dodalabapur, A. J. Lovinger,
J. Am. Chem. Soc
. 1996,118, 11331.
[7] The transport properties of metal/&agr;,&ohgr;-dicyano-6HT/metal structures are highly metal/interface-dependent; TFT carrier signs and mobilities have not been reported: F. Demanze, A. Yassar, D. Fichou,
Synthetic Metals
1999, 101 620.
SUMMARY OF THE INVENTION
As shown from the above discussion, there are a considerable number of problems and deficiencies associated with the prior art relating to useful organic n-type semiconductor compounds, compositions and/or materials, including those discussed above. There is a demonstrated need for such materials, compositions, layers and/or composites for thin film deposition and related applications useful in conjunction with the fabrication of thin film transistors and related devices as can be incorporated into an integrated circuit.
Accordingly, it is an object of the present invention to provide new and useful n-type organic materials, together with one or more methods of preparation, overcoming those various shortcomings and deficiencies of the prior art.
It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can meet certain other objectives. Each objective may not apply equally, in all instances, to every aspect of the present invention. As such, the following objects can be viewed in the alternative with respect to any one aspect of the present invention.
It is another object of the present invention to provide a facile, efficient synthetic method for the preparation of an n-type thiophene conductive material, such preparation resulting in high yield and purity of the desired thiophene material.
It is yet another object of the present invention to provide n-type semiconducting thiophene compounds and related materials and/or thin films which can be used in the fabrication of and in conjunction with a variety of circuitry related devices, including, but not limited to, diode, bipolar junction transistor and field-effect transistor (either junction or metal-oxide semiconductor) devices
It is yet another object of the present invention to provide for the synthetic. modification of organic semiconductive molecular solids to alter electronic behavior, in particular the use of such modified thiophenes to provide and facilitate electron transport.
Other objects, features, benefits and advantages of the present invention will be apparent from the foregoing, in light of the summary and the examples and descriptions which follow, and will be readily apparent to those skilled in the art having knowledge of various semiconducting materials, their preparation and subsequent use. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying examples, tables, graphs, data and all reasonable inferences to be drawn therefrom.
In accordance with one aspect of the present invention, one or more of the foregoing objects can be achieved by use of one or more of the thiophene compounds, compositions and/or materials of the type described herein, and/or with a suitable substrate material as part of a composite or a device incorporating such a composite.
In accordance with another asp
Facchetti Antonio
Marks Tobin J.
Kopec Mark
Northwestern University
Reinhart Boerner Van Deuren
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