Transparent conductive oxides, and

In Table 1.1 a number of properties of zinc oxide are summarized in comparison to other transparent conducting oxides and to silicon. 

The semiconductor nanoparticle most commonly used is the anatase form of Ti02 however, other mesoscopic oxides can also be used, such as Sn02, ZnO, Nb20s, WO3, and Ta20s. Dye molecules are chemisorbed onto the semiconductor (Fig. 6b), forming close to a monolayer. This dye-semiconductor assembly is arranged over a transparent conducting oxide and the set is put into contact... 

Tin(rV) oxide is of significant commercial value because it is an optically transparent, electrical conductor. Its three main applications are in gas sensors, as a transparent conducting oxide, and as an oxidation catalyst. We focus here on the first of these uses. 

Transparent conducting oxides and their appiications in devices... 

Transparent Conducting Oxides and Thin-Film Transistors... 

ZnO, and heterostructure devices. Among the devices, light emitters, microcavities, optically pumped lasers, photodiodes, metal-insulator-semiconductor diodes, field-effect transistors, transparent conducting oxides, and transparent thin-fihn transistors based on ZnO, piezoelectric devices in the form of surface acoustic wave devices, and gas and biosensor followed by solar cells cap the discussion. 

Figure 4 shows the basic constmetion of the devices used in different appHcations, involving the deposition of multilayers of i -SiH of intrinsic (/), doped ), and closely aUied films, such as amorphous siHcon nitride, SiN, and transparent conducting oxide (TCO). As in crystalline... 

Successful electrodeposition of Sb2To3 has been reported for the first time by Leimkiihler et al. [229] who prepared polycrystalline thin films of the material on different transparent conductive oxides, as well as CdTe and Mo, from uncomplexed solutions made by mixing stock solutions of SbCb, Te02, and phthalate buffer (pH 4). The electrochemical process was discussed in detail based on results obtained by cyclic voltammetry on ITO/glass. The bath temperature was found to influence... 

For review of transparent conductive oxides, refer to the special issue of MRS Bull. 25(8), 2000 and the Proceedings of the MRS Workshop on Transparent Conducting Oxides (Denver, CO, June 19-20, 2000). 

Very recently, even transparent conducting oxides (TCOs), such as indium-tin-oxide (ITO), have been prepared using suitable KLE templates.59 As one potential application, such porous TCOs (ZnO, etc.) are interesting for use in dye-sensitized solar cells. In general, such porous electrodes cover a variety of potential electro-optical applications, because they are both conducting and transparent. 

Figure 9.7. Illustration of the usage of mesoporous films of transparent conducting oxides for novel types of solar cells. The dark gray areas correspond to ITO, the brighter ones to an oxide deposited onto the TCO matrix. The sphere symbolizes a dye. For instance, such films can be used as porous electrodes to include dyes and to deposit semiconductors such as ZnO. 

Recently, field-effect transistors based on zinc oxide were reported [173,174], opening the opportunity to design microelectronic devices that are transparent and/or work at high temperatures [175]. More details on thin film transistors employing transparent conducting oxides are given in Chap. 2. 

This process is obviously a natural scattering process in polycrystalline materials, since polycrystalline films exhibit a high concentration of crystallographic defects, especially dislocations [133,134]. However, this process is rarely used to explain experimental data of carrier transport in polycrystalline semiconductors and especially transparent conducting oxides [88], which is mainly due to the fact that in most works on transport properties of polycrystalline films the density of defects was not determined. Podor [135] investigated bended n-type Ge crystals with a dislocation density around 107 cm 2... 

Transparent conducting oxides are widely used as electrodes in thin film optoelectronic devices as solar cells and light emitting diodes because of their transparency for visible light and their high electrical conductivity. Highest optical transparency and electrical conductivity are thus key aspects for such applications. Most work on TCO electrodes is, therefore, dedicated to find deposition parameters, which improve these material parameters. In addition, contact properties are essential for the application of TCOs as electrodes. 

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