Amorphous silicon device technology

The electronic devices are made up of a few different circuit elements, such as transistors, sensors, light emitting diodes etc. Sections 10.1-10.3 describe how the design of these elements is adapted to the specific properties of a-Si H. A few of the actual and potential applications are then discussed. 

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Work is needed on the replacement of toxic or explosive feedstock gases that are used in the manufacture of thin-film systems. Multijunction thin-film systems have to be developed for increased solar-to-electrical conversion efficiency. Continued work is necessary on the fundamental mechanism for the degradation of amorphous silicon devices. There may also be some stability issues with the other thin-film technologies. 

The detector setup consists of four 256 x 256 pixel amorphous silicon technology sensor flat panels with 0.75 x 0.75 mm pixel size, having an active area of 192 x 192 mm [5j. These sensors are radiation sensitive up to 25 MeV and therefor well suited for detecting the LINAC radiation. The four devices are mounted onto a steel Irame each having the distance of one active area size from the other. With two vertical and two horizontal movements of the frame it is possible to scan a total area of about 0.8 x 0.8 m with 1024 x 1024 pixel during four independent measurements. 

FIG. 72. Schematic cross-section of (a) a single junction p-i-n o-Si H superstrata solar cell and (b) a tandem solar cell structure. (From R. E. I, Schropp and M. Zeman. "Amorphous and Microcrystalline Silicon Solar Cells—Modeling, Materials and Device Technology," Kluwer Academic Publishers, Boston, 1998, with permission.)... 

R. E. I. Schropp and M. Zeman, Amorphous and Microcrystalline Silicon Solar Cells—Modeling, Materials and Device Technology. Kluwer Academic Publishers, Boston, 1998. 

Zeman M, Schropp REI (1998) Amorphous and microcrystalline silicon solar cells Modeling, materials and device technology, Kluwer Academic Publishers, Dordrecht,... 

This book describes the properties and device applications of hydrogenated amorphous silicon. It covers the growth, the atomic and electronic structure, the properties of dopants and defects, the optical and electronic properties which result from the disordered structure, and finally the applications of this technologically very important material. There is also a notable chapter on contacts, interfaces, and multilayers. The main emphasis of the book is on the new physical phenomena which result from the disorder of the atomic structure. 

There are several materials which exhibit semiconducting behaviour in glassy state and are technologically important for their proven and potential device applications. The most notable of them are the amorphous silicon and a number of chalcogenide and pnictide glasses. In this chapter, we put together briefly the understanding we have of electron transport in such amorphous semiconductors. 

The diversification of energy sources tailored to the requirements and resources of each country using nature s renewable resources such as the sun (photovoltaics), wind power, geothermal energy and biomass is a definite requirement. If solar cells are chosen to provide an alternative to fossil fuels, significant research work is needed (i) to develop new routes for the production of crystalline silicon, (ii) in the development of amorphous silicon hybrid materials that could result in enhanced efficiencies, (iii) for further development of thin-layer technology, (iv) in concerted efforts for cheaper and more stable dyes, (v) in improving the efficiency of the dye-sensitized cells and (vi) in process development to deliver enhanced device performances, ensure sustainability and reduce production costs on an industrial scale. 

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