Indium coating

A transparent electrode substrate was prepared by coating indium tin oxide (ITO) on a glass substrate and washing the substrate. ITO was then patterned using a photoresist resin and an etchant to specified patterns and the substrate washed. A hole injection layer was formed by coating a selected experimental agent dissolved in toluene to a thickness of about 50 nm and baking at 110°C for 1 hour. 

We examined the field emission properties 29) of the carbon nanotubes prepared in the pores of an alumina membrane whose pore diameter was 230 nm. The wall thickness and the length of the carbon tubes obtained were 15 nm and 60 pm, respectively. The emitting ends of the tubes were open, while the other ends were connected to the same carbonized film formed on the surface of the membrane. As shown in Figure 12, we utilized the gold-coated indium / tin oxide (ITO) as the anode and the carbon tubes as cathode. The gap between the tube ends and the anode was 130 pm. According to the measured results given in Figure 12, the turn on applied electric field is 3 V / pm, which is comparable to... 

In the devices described here, we utilized the simplest sandwich structure for the device configuration with p>oly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT-PSS) coated indium-tin-oxide (ITO) glass as the anode and aluminum as the cathode. The well-known soluble phenyl-substituted polyfpara-phenylene vinylene) (PPV) copolymer ("superyellow" from Merck/Covion) (Spreitzer et al., 1998) was selected as our host light-emitting polymer and an organic ionic liquid, methyltrioctylammonium trifluoromethanesulfonate (MATS), was used to introduce a dilute concentration of mobile ions into the emitting polymer layer. 

Intermetallic compounds with gallium are used as semiconductors. Indium is used to coat other metals to protect against corrosion, especially in engine bearings it is also a constituent of low-metal alloys used in safety sprinklers. The toxicity of thallium compounds has limited the use of the metal, but it does find use as a constituent of high-endurance alloys for bearings. 

AppHcations for electroplated indium coatings include indium bump bonding for shicon semiconductor die attachment to packaging substrates and miscehaneous appHcations where the physical or chemical properties of indium metal are desired as a plated deposit. 

Thermal spray processes can be used to give coatings of chromium carbide or nickel chromium for erosion resistance, copper nickel indium for fretting resistance, tungsten carbide cobalt for wear and abrasion resistance, and even aluminum siHcon polyester mixtures for abradabiHty. 

Some metals used as metallic coatings are considered nontoxic, such as aluminum, magnesium, iron, tin, indium, molybdenum, tungsten, titanium, tantalum, niobium, bismuth, and the precious metals such as gold, platinum, rhodium, and palladium. However, some of the most important poUutants are metallic contaminants of these metals. Metals that can be bioconcentrated to harmful levels, especially in predators at the top of the food chain, such as mercury, cadmium, and lead are especially problematic. Other metals such as silver, copper, nickel, zinc, and chromium in the hexavalent oxidation state are highly toxic to aquatic Hfe (37,57—60). 

Another growing apphcation that overlaps the electrically functional area is the use of transparent conductive coatings or tin oxide, indium—tin oxide, and similar materials in photovoltaic solar ceUs and various optic electronic apphcations (see Photovoltaic cells). These coatings are deposited by PVD techniques as weU as by spray pyrolysis, which is a CVD process. 

The changes in the optical absorption spectra of conducting polymers can be monitored using optoelectrochemical techniques. The optical spectmm of a thin polymer film, mounted on a transparent electrode, such as indium tin oxide (ITO) coated glass, is recorded. The cell is fitted with a counter and reference electrode so that the potential at the polymer-coated electrode can be controlled electrochemically. The absorption spectmm is recorded as a function of electrode potential, and the evolution of the polymer s band stmcture can be observed as it changes from insulating to conducting (11). 

The electrolytic cells shown ia Figures 2—7 represent both monopolar and bipolar types. The Chemetics chlorate cell (Fig. 2) contains bipolar anode/cathode assembhes. The cathodes are Stahrmet, a registered trademark of Chemetics International Co., and the anodes are titanium [7440-32-6] Ti, coated either with mthenium dioxide [12036-10-17, RUO2, or platinum [7440-06-4] Pt—indium [7439-88-5] Ir (see Metal anodes). Anodes and cathodes are joined to carrier plates of explosion-bonded titanium and Stahrmet, respectively. Several individual cells electrically connected in series are associated with one reaction vessel. 

Numerous proprietary electrolytes have been developed for the production of harder and brighter deposits. These include acid, neutral and alkaline solutions and cyanide-free formulations and the coatings produced may be essentially pure, where maximum electrical conductivity is required, or alloyed with various amounts of other precious or base metals, e.g. silver, copper, nickel, cobalt, indium, to develop special physical characteristics. 

Currem field characteristics measured wiih conjugated polymers sandwiched between an indium-tin oxide (ITO) anode and an aluminum cathode are usually hole dominated and are, consequently, appropriate for testing injection/lransport models for the case of unipolar current How. Data shown in Figure 12-1 refer to injection-limited currents recorded on typically 100 nm thick spin-coated films of derivatives of poly(y d/"fi-phenylenevinylene) (PPV) and a planarized poly(/ /" -pheny-leue) employing a Keilhley source measure unit. The polymers were ... 

Electrode coated with lH,lH,2H,2H-perfluorodecanethiol. ) Electrolyticall deposited indium electrode. 

Sn02 and indium tin oxide (ITO) for conductive transparent coatings on glass for electromagnetic interference (EMI) applications. 

The photoelectrochemical properties of CdS nanoparticles formed in LB films of cadmium arachidate on ITO glass (indium tin oxide-coated glass) were investigated [188]. The CdS particles were formed by exposure to H2S gas, and then the cadmium arachidate structure was regenerated by exposing the gas-treated films with aqueous solutions of CdCL. Gassing/immersion cycling increased the particle size from 2.3 0.7 nm after one cycle to 9.8 2.4 nm after five cycles. The 9.8-nm particles showed UV-visible ab-... 

NB. Mixed solvent systems are shown as e.g. acn-aq (0.01 M) where the number in parentheses indicates the concentration of the lesser constituent ITO-Indium/tin oxide-coated glass, Ar- Solutions purged with argon, Ar atm - Experiment performed under an argon atmosphere, N2 atm - Experiment performed under a nitrogen atmosphere b All potentials are measured vs. SCE unless otherwise stated ... 

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