Transparent conductive oxides porous

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. 

The typical dye-sensitized solar cell contains broadly five components (1) a mechanical support coated with transparent conductive oxides (2) the semiconductor porous film composed of oxide, and the most widely researched material is Ti02 (3) a sensitizer adsorbed onto the surface of the semiconductor (4) an electrolyte containing a redox mediator and (5) a counter electrode capable of regenerating the redox mediator like platine [6-8]. 

This chapter is intended to cover major aspects of the deposition of metals and metal oxides and the growth of nanosized materials from metal enolate precursors. Included are most types of materials which have been deposited by gas-phase processes, such as chemical vapor deposition (CVD) and atomic layer deposition(ALD), or liquid-phase processes, such as spin-coating, electrochemical deposition and sol-gel techniques. Mononuclear main group, transition metal and rare earth metal complexes with diverse /3-diketonate or /3-ketoiminate ligands were used mainly as metal enolate precursors. The controlled decomposition of these compounds lead to a high variety of metal and metal oxide materials such as dense or porous thin films and nanoparticles. Based on special properties (reactivity, transparency, conductivity, magnetism etc.) a large number of applications are mentioned and discussed. Where appropriate, similarities and difference in file decomposition mechanism that are common for certain precursors will be pointed out. 

Porous materials with large internal surface areas have attracted considerable attention in surface chemistry, catalysis and chromatography. In principle, a vast choice of porous materials is available. While some inspiration can indeed be drawn from chemical applications, the choices for useful photovoltaic substrate materials are considerably narrowed by the requirement to have thin-film constituency, transparency and electronic conductivity. Indeed, these requirements are so stringent that only a few substrate types and materials have so far been found suitable. Sintered nanocrystalline oxide films are one major class of these. Much development work on these materials has been reported in the context of dye-sensitised cells, and this is... 

LC penetration problems can be solved by using a pillar structure, which has no closed space inside it. The pillar structure can be formed by anodizing of titanium through the porous alumina mask. We have chosen the titania because it is transparent in the visible range and its thermal conductivity is higher with respect to the other valve metal oxides. 

An interesting alternative is the chemical oxidation of heterocycles (e.g. thiophene or pyrrole) dissolved in an organic solvent (e.g. ethanol) on the surface of various materials. Conductive coatings (thickness 0.01 pm) can be produced on films of poly(phenylene sulfone), block copolymers of butadiene and styrene (Ultrason, Styrolux), poly(vinyl chloride), and other polymer films to give transparent, antistatic films with conductivities of about 0.001 S cm . Ceramics and glass can also be coated in this way. In addition, porous... 

---