Pentacene engineered

Saudari SR, Frail PR, Kagan CR (2009) Ambipolar transport in solution-deposited pentacene transistors enhanced by molecular engineering of device contacts. Appl Phys Lett 95 023301... 

Functionalization of pentacene with the specific aim of improving performance in devices is a recent endeavor - the first use of a functionalized pentacene in a field-effect transistor was reported only recently (2003) [26], Functionalization of pentacene has led to the ability to engineer the solid-state arrangement, electronic, and solubility properties of this important semiconductor and to improve its stability and film-forming ability. Recent functionalized pentacene materials have yielded devices with properties comparable with those of the parent acene, have enabled the formation of devices from solution-deposited films, and have even changed the semiconductor behavior of this organic molecule from p-type to n-type. As functionalization strategies are refined, materials with all of the properties necessary for commercial device applications should soon be developed. 

L. Zhou, a-Si H and Pentacene TFT for Flexible Electronic Applications, in Electrical Engineering Department. University Park, Pennsylvania State University, 2005. 

The HPLC methods cannot be used to routinely monitor the other PAHs because the instrumentation is rather sophisticated and data interpretation and analysis requires a high level of expertise. Instead simple UV absorbance methods are used to measure the absorbance at wavelengths characteristic of certain key PAHs. These include 305 nm for coronene, 335 nm for pyrene, 345 nm for dibenzo[cdJm]perylene, and 495 nm for dinaphtho[2,l,8,7-defg 2, r8, 7 -opqr]pentacene. Tracking of each of these absorbances from process startup allows process engineers to follow the buildup of the PAHs and gain an idea of the chemistry going on within the process. 

In order to compensate the initially proposed interfacial electron traps on the Si02 dielectric, Ahles et al. [62] introduced traces of Ca to the Si02 dielectric interface. As a low work function metal, Ca was believed to act as an electron donor saturating traps in the interface near pentacene layer. The capability to accumulate mobile charge carriers at the newly engineered interface can again be examined by MIS diode experiments. The result of impedance measurements on a MIS diode... 

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