Transparent conducting thin films electrical properties

At the same time, SWNT can be used at the top electrode (that needs to be transparent) as a replacement for the currently used thin films that are also electrical conductors. Typical conductive thin films used today are oxides such as fluorine-doped tin oxide (FTO), Al-doped zinc oxide, and the indium tin oxide (ITO) mentioned above. The disadvantages of these oxide films are that they require expensive deposition procedures at high vacuum, they have poor mechanical properties, and they are not transparent in the infrared. Another interesting difference is that transparent oxide conductors are n-type semiconductors. By contrast, nanotube networks act as p-type semiconductors, which could lead to new designs. 

C. Mattevi, G. Eda, S. Agnoli, S. Miller, K.A. Mkhoyan, 0. Celik, et al., Evolution of electrical, chemical, and structural properties of transparent and conducting chemically derived graphene thin films, Advanced Functional Materials, 19 (2009) 2577-2583. 

In this book the chemical, structural, optical, electrical, and interface properties of zinc oxide are summarized with special emphasis on the use of ZnO as transparent conductive electrode in thin film solar cells. This application has a number of requirements, which can be fulfilled by ZnO ... 

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. 

In addition to silicon and metals, a third important element being deposited as thin films is diamond (Celii and Butler, 1991 May, 2000). For many years, diamonds were synthesized by a high pressure/high temperature technique that produced bulk diamonds. More recently, the interest in diamonds has expanded to thin films. Diamond has a slew of properties that make it a desired material in thin-film form hardness, thermal conductivity, optical transparency, chemical resistance, electrical insulation, and susceptibility to doping. Thin film diamond is prepared using chemical vapor deposition, and we examine the process in some detail as a prototypical chemical vapor example. Despite its importance and the intensity of research focused on diamond chemical vapor deposition, there remains uncertainty about the exact mechanism. 

Indium-tin oxide (ITO) is indium oxide doped with tin oxide. Thin films of ITO have commercially valuable properties it is transparent, electrically conducting and reflects IR radiation. Applications of ITO are varied. It is used as a coating material for flat-panel computer displays, for coating architectural glass panels, and in electrochromic devices. Coating motor vehicle and aircraft windscreens and motor vehicle rear windows allows them to be electrically heated for de-icing... 

Transparent conductive coatings combine high optical transmission with good electrical conductivity. The existence of both properties in the same material is, from the physics point of view, not trivial and is only possible with certain semi-conductors like indium oxide, tin oxide, cadmium oxide, and with thin gold and silver films, e.g. [157]. Particularly antimony or fluorine doped tin oxide (ATO, FTO), tin doped indium oxide (ITO), and aluminium, indium, or boron doped zinc oxide (AZO, IZO, BZO) are of technical importance [157a]. 

Thin networks of SWNT can be prepared as transparent and highly conducting films which, in addition, have very good mechanical properties. They can be prepared in a reproducible way by a rather simple method of fabrication at room temperature that does not require high vacuum conditions or expensive equipment. Moreover, SWNT thin films have no equal in the tunability of their electrical, optical, and mechanical properties. By varying the type of nanotube used or the film preparation procedures, researchers can vary electrical and optical responses by several orders of... 

Alam M.J., Cameron D.C. Optical and electrical properties of transparent conductive ITO thin films deposited by sol-gel process. Thin Solid Films 2000 00 455 59 Alam M.J., Cameron D.C. Investigation of annealing effects on sol-gel deposited indium thin oxide thin films in different atmospheres. Thin Solid Films 2002 420-421 76-82 Anderson H.U., Pennell M.J., Guha J.P. Polymeric synthesis of lead magnesium niobate powders. Adv. Ceram. 1987 21 91-98... 

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