Contact structures

They are the only devices that are independent of the operating system, as the breaking eapacily is dependent mainly on the material and contour of the contact structure and the quality of the vacuum. 

The catalytic activity markedly depends on the contact structure of gold with the supports. Remarkably high activity emerges when hemispherical gold NPs are attached to the support at their flat planes. This contact structure is often epitaxial as... 

A hypothesis that edge and corner sites work as active sites can explain why turn over frequency (TOF), which is defined as the reaction rate per one active site, in the case of metal catalysts, per surface exposed metal atom, increases with a decrease in the diameter of gold particles. However, it fails to explain the significant contribution of support materials and the contact structure of gold NPs. It seems to be reasonable that those edges and corners act as the sites for adsorption of one of the reactants, for example, CO in its oxidation. 

Figure 16. Effect of contact structure on the catalytic activity in CO oxidation over supported Pt and Au NPs.

Li Z, Zou B, Wang C (2006) Electronic transport properties of molecular bipyridine junctions effects of isomer and contact structures. Phys Rev B 73 075326-075327... 

Among other specific applications of PTs as light-emitting materials, it is necessary to mention microcavity LEDs prepared with PTs 422 and 416 [525,526] and nano-LEDs demonstrated for a device with patterned contact structure, and PT 422 blended in a PMMA matrix that emits from phase-separated nanodomains (50-200 nm) [527,528]. 

In the propylene reaction with a 02-H2 mixture, the contact structure of Au NPs and the selection of support metal oxides are critical for producing propylene oxide (PO). 

The actual retina contact structure incorporates 12 or 24 independent electrodes, respectively. The electrodes were arranged concentrically to minimize the electrical stray field during stimulation. We established the microfabrication process for double metallization layers needed to obtain concentric microelectrodes. In a temper step, the electrodes were formed into a convex shape according to the curvature of the eye. The generation of convex shapes was possible since the stimulator was designed in concentric rings interconnected by s-shaped bridges (Fig. 26). 

To segregate our possible contact effects, the same experiment was repeated with gold top-contact-structure pentacene TFTs also. A 0.5-pm film of parylene-C was deposited and the TFTs were measured without a patterning of the parylene. The TFT (W/L = 400/80 pm) characteristics before and after parylene passivation are compared in Fig. 15.10. Field-effect mobility has a 40% decrease from 2.3 cm2 V-1 s 1 to 1.4 cm2 V 1 s 1, while the threshold voltage stayed the same. 

Fig. 6. The current-voltage characteristics of a-Si H blocking contact structure target.

Effects of Size and Contact Structure of Supported Noble Metal Catalysts in Low-Temperature CO Oxidation... 

Effect of Contact Structure of Noble Metal Particles with the Supports... 

EFFECT OF CONTACT STRUCTURE OF NOBLE METAL PARTICLES WITH THE SUPPORTS... 

Even though the component and size of metals and metal oxide support are defined, the catalytic activity for CO oxidation often markedly changes depending on the contact structure of noble metal particles with the supports. In particular, Pd, Ir, and Au exhibit high catalytic activity when they are deposited on reducible metal oxides by coprecipitation, deposition-precipitation, and grafting. Goulanski has classified supported metal catalysts for low-temperature oxidation into three groups [72], There are three possible active sites metal surfaces with metal oxide as a simple support metal oxide thin layer underneath of which metal particles are buried and the perimeter interfaces around noble metal particles. 

In the first case where metal surfaces provide active oxygen species to the support contact structure is not critical. The second case is often observed when supported metal catalysts are prepared by coprecipitation or sol-gel methods. Noble metals whose oxides are more stable than Pt oxides such as Pd and Ir are more readily buried in the bulk of metal oxide supports, and the metal oxide overlayers of a thickness of about a few monolayers are modified in their electronic and redox properties by underlying noble metal nanoparticles to become active at lower temperatures. 

In this paper, hydrogenated amorphous silicon thin film transistors (a-Si H TFTs) fabricated on a metal foil substrate is reported for active matrix OLEDs (AMOLEDs) displays. The electrical properties of a-Si H TFTs fabricated on a metal foil substrate are introduced. To increase the stability of a-Si H TFTs fabricated at low temperature on a metal foil substrate, negative bias applied to metal foil substrate can also recover the shifted threshold voltage during idle time. A new cathode-contact structure employing a normal top-emitting OLED, which is suited to n-type a-Si H TFT backplane is proposed. 

In this section, we propese a new cathode-contact structure employing the normal TOLED (CCTOLED) that has an anode at bottom and a cathode on top (Fig. 21 )). We also compare the electrical characteristics between the CCTOLED and ACTOLED pixel structure. 

Fig. 22. Fabrication process flow of a newly proposed normal top-emission OLED pixel employing cathode-contact structure (a) a-Si H TFT, (b) reflective anode, (c) step-covering layer and separator, (d) organic layer evaporation through the shadow mask on the anode, (e) cathode evaporation.

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