Pentacene solution-processed

Minakata, T. and Natsume, Y. (2005) Direct formation of pentacene thin films by solution process. Syn. Met., 153, 1—4. 

Afzali, A. Dimitrakopoulos, C. D. Breen,T. L. 2002. High-performance, solution processed organic thin film transistors from a novel pentacene precursor. J. Amer. Chem. Soc. 124 8812-8813. 

An alternative route to solution-processible organic semiconductors is to use precursors to small molecule semiconductors, such as pentacene [59] or tetrabenzo-porphyrin [60], which can be converted into their fully conjugated, insoluble form by thermal or irradiative [61] treatment on the substrate. Pentacene precursors have been shown to yield field-effect mobilities of 0.01-0.1 cm2 V-1 s 1 [62], and 0.1-0.8 cm2 V-1 s 1 [63] after thermal conversion at 150-200 °C. Small molecule organic semiconductors can also be rendered solution processible by attachment of flexible side chains [64-66], Due to the relatively low solubility of these molecules the growth of uniform thin films of these molecules remains challenging, however. 

Using impedance spectroscopy we measured transistors with solution processed pentacene as the semiconductor. Fabrication details are discussed in Section 13.3.1. We have made use of a ring-type transistor, in which the source electrode forms a closed ring around the transistor channel and the drain electrode, at which the current is monitored. Using this geometry, the measurements are insensitive to parasitic currents that may flow outside the transistor area [29]. 

Typical transfer and output characteristics of a solution-processed pentacene FET with channel length L = 20 pm and W = 1000 pm are shown in Fig. 13.7. The characteristics were obtained under ambient conditions. The field effect mobility of the FET is 0.01 cm2 V-1 s-1 at Vg = —20 V. On less typical wafers mobilities as high as 0.25 cm2 V-1 s 1 have been observed. The drain current modulation 1d(Vd = —1 V, Vg = -20 V)/ID(VD = —1 V, VG = 10 V) of 10s is routinely obtained. By improving the uniformity and by reducing the parameter spread the integration level could be increased to about 103 transistors. 

Park SK, Jackson TN, Anthony JE, Mourey DA. (2007) High mobility solution processed 6,13-bis(triisopropyl-silylethynyl) pentacene organic thin film transistors. Appl Phys Lett 91 063514. 

A. Afzali, C. D. Dimitrakopoulos, and T. L. Breen. High-Performance, Solution-Processed Organic Thin Film Transistors from a Novel Pentacene Precursor. Journal of the American Chemical Society, 124(30) 8812-8813, 2002. 

Technical issues in printed electrodes were briefly reviewed for all-printed TFT applications. Surface morphology and edge waviness of the printed electrode should be well controlled to produce uniform and stable TFT behavior and consistent thin-film device performances. This investigation fabricated solution-process TIPS-pentacene based TFT with the printed silver electrodes. Solution-process materials can be readily combined with a low-cost printing process, which can significantly reduce complexity in the fabrication and manufacturing process. In addition, these types of solution-process TFT can be fabricated at low temperatures and they can be also readily implemented on plastic substrates for flexible electronics applications. 

Besides pentacene, some other small molecular organic semiconductors can also be rendered solution processable by attachment of flexible side chains. But they are no longer still used for realizing fibrous transistors. For more detailed information see (Sirringhaus, 2005). 

The [3-1-2] and [4-1-2] cycloaddition reactions of IV-sulfinylamines are also well investigated. High pressure is used to assist the cycloaddition reactions of azulene-substituted A -sulfinylamines . The [4-1-2] cycloaddition reaction of MeCONSO with pentacene (yield >90 %) is used to synthesize a solution-processable organic thin film transistor. ... 

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