Charge mobile type

The fact that active and selective catalysts in general comprise two or more oxide components is certainly not a sufficient argument to assume bifunctionality the combination of oxides may also cause modification of sites or formation of one type of new sites which combine the specific properties required for a sequence of reaction steps. Such properties may concern the geometry, the type of oxygen bonding, oxygen and charge mobility in the solid, acidity, etc. 

Considering their possible applications in fuel cells, hydrogen sensors, electro-chromic displays, and other industrial devices, there has been an intensive search for proton conducting crystals. In principle, this type of conduction may be achieved in two ways a) by substituting protons for other positively charged mobile structure elements of a particular crystal and b) by growing crystals which contain a sufficient amount of protons as regular structure elements. Diffusional motion (e.g., by a vacancy mechanism) then leads to proton conduction. Both sorts of proton conductors are known [P. Colomban (1992)]. 

Depending on the chemical modification of the conjugated core, either n- or p-type behavior is observed, while the fluorine-free acyl analogs behave as either ambipolar or p-type semiconductor. Insertion of the dioxolane group into the thiophene core inverts the majority charge carrier type from electrons (371) to holes (372) in a very similar fashion to 369. The 373 data reveal that n-type activity is recovered with mobility and on-off ratio 0.07 cm2 V 1 s-1 and 106. 

Here I, represents the drain current and ju, jUp the respective electron and hole mobility. C defines the area capacitance of the insulator. The channel geometry is defined by the channel width W and length L. The ambipolar range, described by Eq. (3), is only valid as long as both electrons and holes can be injected and further transported in the active layer of the transistor. However, in most cases the injection and/or the transport in the transistor channel are suppressed for one charge carrier type. In that case, the FET operates only in the unipolar and saturation range as described by Eqs. (1) and (2). 

In contrast to inorganic molten salts, the fluidity of ionic hquids at room temperature permits their use as solvents for chemical reactions. Electrostatic properties and charge mobility in ionic hquids can play a distinctive role in chemical reactivity, as compared with neutral solvents. In particular, hydrogen and proton transfer reactions are likely to be sensitive to an ionic environment due to the hydrogen-bond acceptor ability of the anions. Such type of reactions are fundamental in acid-based chemistry and proton transport in solution. 

It is important to be able to probe defects in graphene because they strongly affect charge mobility. Furthermore, defect-engineering can allow one to tune the properties of graphene simply by introducing specific types and amounts of defects in the crystal lattice [68]. 

The retention on ion exchangers is a function of charge and type of the stationary phase, the degree of ionization of the analytes, and the type and concentration of ions in the mobile phase, as well as analyte molecular size. 

Several different materials can be used as transparent electrodes, most of them as anode material ITO [113,194,195,200], pofyaniline and polyaniline blends [206, 207, 209, 210], TO [201, 202,204], and F-doped TO [112,205]. The use of transparent material as a cathode has also been reported [202]. In the case of PPV and several of its derivatives, the effective mobility of the electrons is lower than that of the holes, implying a reduction in the extent of the recombination zone in the electroluminescent polymer layer, as observed in PPP LEDs [164]. Further, the values of polymer electroaffinity and ionization potential make the injection and transport of holes etisier than that of electrons in single-polymer-layer devices. The injection dynamics also depends on the injected carrier that remains in the polymer (space charge), modifying the electric field distribution in the device [217]. For these reasons, different materials are tested as cathode and anode and, in several cases, intermediate layers are also introduced in order to improve the injection of a specific charge carrier type or to block its transport through the device [212,213,218-220]. 

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