Solar cell construction

The preparation and structure of Si3N4 were discussed at the end of Section 14.12. Its uses as a refractory material are widespread, as are its applications in the microelectronics industry and solar cell construction. Thin films of Si3N4 can be prepared by reacting SiHi or SiCLi with NH3... 

Goris, L., et al. 2003. Poly(5,6-dithiooctylisothianaphthene), a new low band gap polymer Spectroscopy and solar cell construction. Synth Met 138 249. 

Successful commercialization of low cost, high efficiency solar cell fabrication is highly dependent on fabrication methods that employ continuous processing techniques. One major issue encountered in solar cell construction is the adhesion of thin film solar cells on polyimide substrates. Another involves the adhesion between polymer nanocomposite solar cell structures. The examination of the adhesion promotion potential of variable chemistry atmospheric plasma surface modifications against wet primer chemistry in solar cell construction has shown that APT is a viable continuous and environmentally friendly processing alternative to batch plasma and surfactant-based surface modification protocols. 

These environmentally friendly properties lead to the concept of Green Chemistry , manifested in the appearance of a journal of the same name, published by the Royal Society of Chemistiy. All various aspects of ILs including their use in catalysis, biotechnology, polymer chemistry, solar cell construction, chemical kinetic, etc. have been discussed in many books. It has become clear that it is possible to create specific compositions of various ILs exhibiting various physical, chemical, biochemical and pharmaceutical properties. Terms such as tuneable green solvents have been used to describe these possibilities. Within the last 20 years the number of publications dealing with ILs has tremendously inereased. Several excellent reviews on the development of ILs, their history as well as on their expanding applications are available. ... 

The current needed for cathodic protection by impressed current is supplied from rectifier units. In Germany, the public electricity supply grid is so extensive that the CP transformer-rectifier (T-R) can be connected to it in most cases. Solar cells, thermogenerators or, for low protection currents, batteries, are only used as a source of current in exceptional cases (e.g., in sparsely populated areas) where there is no public electricity supply. Figure 8-1 shows the construction of a cathodic impressed current protection station for a pipeline. Housing, design and circuitry of the rectifier are described in this chapter. Chapter 7 gives information on impressed current anodes. 

Photovoltaic systems for specific applications are produced by connecting individual modules in series and parallel to provide the desired voltage and current (Figure 4). Each module is constructed of individual solar cells also connected in series and parallel. Modules are typically available in ratings from a few peak watts to 250 peak watts. 

The optical properties of electrodeposited, polycrystalline CdTe have been found to be similar to those of single-crystal CdTe [257]. In 1982, Fulop et al. [258] reported the development of metal junction solar cells of high efficiency using thin film (4 p,m) n-type CdTe as absorber, electrodeposited from a typical acidic aqueous solution on metallic substrate (Cu, steel, Ni) and annealed in air at 300 °C. The cells were constructed using a Schottky barrier rectifying junction at the front surface (vacuum-deposited Au, Ni) and a (electrodeposited) Cd ohmic contact at the back. Passivation of the top surface (treatment with KOH and hydrazine) was seen to improve the photovoltaic properties of the rectifying junction. The best fabricated cell comprised an efficiency of 8.6% (AMI), open-circuit voltage of 0.723 V, short-circuit current of 18.7 mA cm, and a fill factor of 0.64. 

A more recent paper considered the use of a hybrid power supply for powering autonomous microsen-sors. ° Such devices are similar to the dust mote pictured in Figure 1 and described in the Introduction. This hybrid power supply combined a solar cell to meet standby requirements and to charge the battery, which was the microfabricated Ni—Zn battery described in section 3.2. The authors also showed that if the battery alone was to serve as the power source, the footprint would be substantially larger, over 12 cm . The hybrid device was constructed and some feasibility experiments were carried out, but no actual devices were powered. 

The dye-sensitised solar cell (DSSC) is constructed as a sandwich of two conducting glass electrodes filled with a redox electrolyte. One of the electrodes is coated, using a colloidal preparation of monodispersed TiOj particles, to a depth of a few microns. The layer is heat treated to rednce resistivity and then soaked in a solution of the dye until a monomolecnlar dispersion of the dye on the TiO is obtained. The dye-coated electrode (photoanode) is then placed next to a connter electrode covered with a conducting oxide layer that has been platinised , in order to catalyse the reduction of the mediator. The gap between the two electrodes is filled with an electrolyte containing the mediator, an iodide/triodide conple in acetonitrile. The structure is shown schematically in Fignre 4.29. 

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