Dielectric materials organic transistors

Bao Z, Kuck V, Rogers J A and Paczkowski M A, Silsesquioxane resins as high performance solution processable dielectric materials for organic transistor applications , Adv Func Mater, 2002 12 526-531. 

Organic Transistors Based on Molecular and Polymeric Dielectric Materials... 

Abstract. The design and synthesis of new molecular synthons for vapor-phase self-assembled nanodieletrics and silane crosslinkers for crosslinked polymer blend dielectrics is described. These dielectric films exhibit excellent dielectric properties with tunable thicknesses and capacitance values. These new gate dielectric materials are integrated into thin-film transistors based both p- and n-type organic semiconductors. 

Ruiz, R., Choudhary, D., Nickel, B. et al., Pentacene thin film growth, Chem. Mater. 16, 4497, 2004 Laquindanum, J.G., Katz, H. E., Dodabalapur, A., and Lovinger, A. J., -Channel organic transistor materials based on naphthalene frameworks, J. Am. Chem. Soc. 118, 11331, 1996 Fritz, S.E., Kelley, T.W., and Erisbie, C.D., Effect of dielectric roughness on performance of pentacene TFTs and restoration of performance with a polymeric smoothing layer, J. Phys. Chem. B 109,10574, 2005 Nickel,... 

Table 6.3. Device performance, structure, and test parameter table for IEEE 1620 compliance, adapted from [114], Fig. 4. At least two of the specific gate insulator capacitance, relative dielectric constant, and gate dielectric thickness are required. Reprinted with permission from IEEE Standard 1620-2004, IEEE Standard for Test Methods for the Characterization of Organic Transistors and Materials, Copyright 2004 by IEEE.

For use with organic transistors, die dielectric material must also be conqiatible with organic semiconductors. Specifically, the dielectric films must have a low sur ce trying density, low surfiice roi hness, and a low inqiurity concentration and must not degra die performance of the adjacent, ordered organic semiconducting films. 

Identification of solution processable dielectric materials is also crucial to the commercial application of high performance, low cost, organic thin film field effect transistors. The fiiin dielectric films must be pinhole fiee and have a high breakdown voltage and good long-term stability. To permit fire use of plastic substrates in these devices, it is also desirable that the films can be formed at... 

Bartic C, Jansen H, CampiteUi A, Borghs S (2002) Ta205 as gate dielectric material for low-voltage organic thin-film transistors. Org Electron 3 65-72... 

Several polymer conductors are commercially available, and have been used in the demonstration of printed transistors. These include PEDOT PSS, which is a commercially available polymer conductor, as well as various versions of polyaniline. The latter is typically doped with an acid or salt to increase conductivity. Both of these material systems are water soluble and easily printable. They also typically form good interfaces to organic semiconductors, making them attractive for use in printed transistors. As with polymer dielectrics, however, it is important to note that their usability with inorganic semiconductors is questionable, of course. 

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