Organic field-effect transistor performance

Ebata H, Izawa T, Miyazaki E, Takimiya K, Ikeda M, Kuwabara H, Yui T (2007) Highly soluble [l]benzothieno[3,2-b]benzothiophene (BTBT) derivatives for high-performance, solution-processed organic field-effect transistors. J Am Chem Soc 129 15732-15733... 

To reach this frequency is in no way trivial, and in particular requires a minimum mobility of charge carriers within the organic field effect transistors. This important issue will be discussed below. It has to be noted, however, that in view of the technological applications, a reliable and constant device performance may be even more important than a peak performance of the individual circuits. 

Over the last two decades the charge carrier mobilities of organic materials have shown a rather rapid increase today organic field effect transistors can be built with performances [14, 15] that can compete with FETs based on polycrystalline silicon [16]. 

The first section of the book is devoted to industrial applications. In two articles written by two of the major companies active in this field, PolylC and Evonik, the applications that presently attract the most interest fi om a commercial point of view are described. At the same time, the key problems related to the manufacturing of cheap electronics through a printing process are addressed. These two chapters provide an excellent introduction to the more applied aspects of the field and also define the Ifamework for the following chapters in the book, which all address problems that in one way or the other are related to producing organic field effect transistors and to improving their performance and stability. 

A. Ullman, et al., ffigh Performance Organic Field-Effect Transistors and Integrated Inverters , in Electronic,... 

In recent years great effort has been devoted to conjugated polymers as organic field-effect transistor (OFET) active layers [1]. An important parameter relevant to the operation of an OFET is the charge carrier mobility which determines the overall performance of any polymer-based devices. 

Assembly, Structure, and Performance of an Ultra-Thin Film Organic Field-Effect Transistor (OFET) Based on Substituted Oligothiophenes... 

DCNDBQT organic field effect transistors (OFETs) were fabricated on a highly doped n-Si wafer with 30 nm silicon dioxide. Firstly, the silicon surface was rinsed with Dl-water, acetone and iso-propanol in order to remove small particles and organic impurities. Secondly, the substrate was treated with oxygen plasma and silanised for 26 hours at 60 °C by hexamethyldisilazane (HMDS) in order to improve the OFET performance [21]. As source-drain contacts of the bottom contact transistors (BOC) gold was used, which was evaporated through a shadow mask on the silieon dioxide (see Figure 5.2). 

J.P., Scherf, U. and Neher, D., Effect of molecular weight and annealing of poly (3-hexylthiophenejs on the performance of organic field-effect transistors, Adv. Func. Mater, 14, 757-764, 2004. 

Naraso et al., High-performance organic field-effect transistors based on pi-extended... 

A new class of semiconductors for organic field-effect transistors (FET) has been developed and studied. Thus metalation of the 1,4-dibromobenzene derivative 141, followed by Introduction of the appropriate chalcogens gave the fused systems 142, which displayed promising FET performances, in particular the selenophene derivative <04JA5084>. 

Organic field effect transistor (OFET) devices have been fabricated from pBTTT polymer solutions and hole mobility values of up to 0.8cm /V s were reported in a nitrogen atmosphere. These values approach that of high performing evaporated small molecule devices and are comparable to amorphous silicon. In bottom gate, bottom-contact devices, in which the active semiconductor layer is the exposed top surface, the effect of different ambient conditions has been evaluated. Exposure to unpurified, ambient air in which the humidity is -50%, results in an initial increase in the off-current of the device. In filtered, low humidity air, transistor devices remain very stable over time. 

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