Silver back electrode

Silver pastes are commonly used in photovoltaics applications as top electrodes. The typical resistivity of the commercial highly conductive Ag paste is around 4.5x10 cm (see http //www2.dupont.com). In the case of OPVs, silver paste is also used as an anode. Because this silver paste has a relatively large viscosity, it is commonly screen printed. However, the silver paste consists of many micron-sized silver flakes which are easily able to penetrate to the underlying polymer layer this can cause an electrical shorting problem 

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Ink formulations that can be used for the fabrication of solar cells have been described in detail (37). These are a silver back electrode ink, a zinc oxide nanoparticle ink, a polymeric ink from poly(3-hex-ylthiophen-2,5-diyl) and a fuUerene derivative, a PEDOT-KS, and a silver grid front electrode ink formulation. 

Electrodes and Galvanic Cells. The Silver-Silver Chloride Electrode. The Hydrogen Electrode. Half-cells Containing an Amalgam, Electrode. Two Cells Placed Back to Back. Cells Containing Equimolal Solutions. The Alkali Chlorides as Solutes. HC1 in Methanol or Ethanol Containing a Trace of Water. The Alkali Chlorides in Methanol-Water Mixtures. The Heal of Solution of HC1. Proton Transfer Equilibrium from Measurements of E.M.F. 

The calomel electrode consists of mercury and mercury (I) chloride (calomel Hg2Cl2) in contact with a potassium chloride solution of constant activity. In case that the supporting electrolyte in the cell contains perchlorate anions, it is advisable to use NaCl instead of KCl since KCIO4 is sparingly soluble and could precipitate in the diaphragm. In most cases, satmated KCl solution is used however, in such solution already at temperatures above 35 °C, a disproportion reaction takes place. The back reaction by cooling down the electrode is very slow so that a hysteresis of the electrode potential occurs. This is the reason why it is reconunended that the calomel electrode only be used at temperatures in maximum up to 70 °C. In Table 1 electrode potentials of the silver/silver chloride electrode and for the calomel electrode at different temperatures and different concentrations of KQ are given. Note that the electrode potentials differ when other salts than potassium chloride (e.g., NaQ) are used because of the different solubility products. 

Cyanide detection is accomplished by using an FIA system in which a 200 pi aliquot of the pretreated sample is injected. The addition of hydrochloric acid converts cyanide ion to hydrogen cyanide (HCN) that passes selectively through a gas-diffusion hydrophobic membrane into an alkaline-receiving solution where it is converted back to cyanide ion. The latter is monitored amperometri-cally with a silver-working electrode, silver/silver chloride reference electrode, and platinum/stainless steel counter electrode, at an applied potential of zero volt. The current generated is proportional to the cyanide concentration present in the original sample. 

Of course, in the case of gas sensors operated at room temperature we do not have such strong requirements from electrode materials, and therefore other materials, which are not as stable as Pt, can be used. In particular, gold (front and back) electrodes are used in most conventional QCMs. Other electrode materials such as aluminum, copper, silver, chromium, nickel, titanium, tungsten, zinc, as well as carbon and sihcon can also be used in gas sensors (ICM, htq> //www.icmfg.com/crystalsJitml). 

The hydrogen electrode is still the basis for all pH measurements to date. The pH of the standard buffers used to calibrate pH electrodes is traced back to primary buffer solutions [11]. The primary method for pH is based on the measurement of the potential of an electrochemical cell without liquid junction, involving a selected buffer solution, a platinum hydrogen electrode, and a silver/silver chloride reference electrode. The standard potential of the silver/silver chloride electrode in hydrochloric acid at a molality of 0.01 mol kg is determined simultaneously. 

The potentiometric micro detection of all aminophenol isomers can be done by titration in two-phase chloroform-water medium (100), or by reaction with iodates or periodates, and the back-titration of excess unreacted compound using a silver amalgam and SCE electrode combination (101). Microamounts of 2-aminophenol can be detected by potentiometric titration with cupric ions using a copper-ion-selective electrode the 3- and... 

Lebel [224] has described an automated chelometric method for the determination of sulfate in seawater. This method utilises the potentiometric end-point method for back titration of excess barium against EDTA following precipitation of sulfate as barium sulfate. An amalgamated silver electrode was used in conjunction with a calomel reference electrode in an automatic titration assembly consisting of a 2.5 ml autoburette and a pH meter coupled to a recorder. Recovery of added sulfate was between 99 and 101%, and standard deviations of successive analyses were less than 0.5 of the mean. 

A Platinum electrodes backed with glass for maximum rigidity. B Silver soldered platinum-copper junction... 

In addition, the separator must have a low electrical resistance, good thermal and chemical stability and must be light in order to retain the high energy density characteristics of the cell. Practical separators have a composite multilayer configuration. A silver-stopping layer of cellophane or non-woven synthetic polyamide is located next to the positive electrode which reduces soluble silver species back to the metal. A potassium titanate paper layer may be placed next to the zinc electrode, and a number of cellophane layers which swell in aqueous KOH make up the middle section. In most cells the separators are fabricated as envelopes or sacks which completely enclose the zinc electrodes. 

Following deposition, the Ti02 coated plates were subjected to a reduction treatment under H2 at 600°C for 2 hours. After verification of a good electrical contact at the back surface of the Ti sheet, a copper plate with an electrode lead was attached to the electrode back with silver paint. The electrode back and edges were covered with silicone rubber adhesive (GE RTV 108). 

The establishment of a stable equilibrium potential between the metal electrode and the electrolyte can be straightforwardly explained as follows. As soon as the neutral silver electrode gets in contact with the electrolyte, the reaction Ag+ + e —> Ag will proceed, while the rate of the back reaction is negligibly small. The excess positive charge injected into the silver electrode will render the potential of the electrode... 

Germanium — (Ge, atomic number 32) is a lustrous, hard, silver-white metalloid (m.p. 938 °C), chemically similar to tin. Ge is a low-band-gap - semiconductor that, in its pure state, is crystalline (with the same crystal structure as diamond), brittle, and retains its luster in air at room temperature. Anodic dissolution of the material occurs at potentials more positive than ca. -0.2 V vs SCE. Peaks in the voltammograms of germanium in acidic electrolyte are ascribed to a back-and-forth change between hydrogenated and hydroxy-lated surfaces [i]. Studies are often conducted at p-doped and n-doped Ge electrodes [ii] or at Ge alloys (e.g., GeSe) where photoelectrochemical properties have been of considerable interest [iii]. 

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