Silicon crystalline module

Nijs, J. Mertens, R. Van Overstraeten, R. Szluf-cik, J. Hukin, D. Frisson, L. Energy payback time of crystalline silicon solar modules. Adv. Solar Energy 1998, 11, 291-327. 

A few years ago, Motohiro and co-workers reported a comparison between solar modules assembled with DSSC, with modules made of crystalline silicon solar cells conunercialized by Siemens. During 6 months of outdoor exposure in the rooftop of a building located in the southern part of Kariya, Japan, the authors observed that the DSSC module generated 10-20% more energy than the commercial silicon-based module. These results are very promising and stimulate the research to bring DSSC into the market. 

Amorphous Silicon. Amorphous alloys made of thin films of hydrogenated siUcon (a-Si H) are an alternative to crystalline siUcon devices. Amorphous siUcon ahoy devices have demonstrated smah-area laboratory device efficiencies above 13%, but a-Si H materials exhibit an inherent dynamic effect cahed the Staebler-Wronski effect in which electron—hole recombination, via photogeneration or junction currents, creates electricahy active defects that reduce the light-to-electricity efficiency of a-Si H devices. Quasi-steady-state efficiencies are typicahy reached outdoors after a few weeks of exposure as photoinduced defect generation is balanced by thermally activated defect annihilation. Commercial single-junction devices have initial efficiencies of ca 7.5%, photoinduced losses of ca 20 rel %, and stabilized efficiencies of ca 6%. These stabilized efficiencies are approximately half those of commercial crystalline shicon PV modules. In the future, initial module efficiencies up to 12.5% and photoinduced losses of ca 10 rel % are projected, suggesting stabilized module aperture-area efficiencies above 11%. 

Commercially available PV systems most often include modules made from single-crystal or poly-ciystalline silicon or from thin layers of amoiphous (non-crystalline) silicon. The thin-filni modules use considerably less semiconductor material but have lower efficiencies for converting sunlight to direct-current electricity. Cells and modules made from other thin-filni PV materials such as coppcr-indiuni-diselenide and cadmium telluride are under active development and are beginning to enter the market. 

Crystalline silicon modules are typically produced in a complex and articulated manufacturing chain [4], all of which have greatly improved over the years - and which still have margins for further improvements. 

Microstructures and systems are typically fabricated from rigid materials, such as crystalline silicon, amorphous silicon, glass, quartz, metals and organic polymers. Elastomeric materials can be used in applications where rigidity is a drawback. We have demonstrated the concepts of elastomeric systems by fabrication of photothermal detectors, optical modulators and light valves. We believe that elastomeric materials will find additional applications in the areas of optical systems, micro analytical systems, biomaterials and biosensors. 

Thin-film solar shingles used on residential roofs today are only about 5 to 8% efficient. The efficiency of solar towers is also about 5%. Photovoltaic (PV) cell efficiencies range from about 5% for amorphous silicon (A-Si) designs, 9% to 10% for CdTe modules, and 13% to 16% for crystalline silicon modules. SEGS efficiencies are between 10 and 25%. 

Although ZnO has also been applied in so-called amorphous/crystalline heterojunction solar cells consisting of a (doped) silicon wafer and thin doped a-Si H layers to build the p-n junction, we will restrict ourselves here to solar cells and modules with amorphous and/or microcrystalline absorber layers, i.e., real thin film silicon solar cells. For detailed information on the use of ZnO in crystalline silicon wafer based devices, the reader is referred to the literature (see e.g. [23,24]). 

Reference can be made to the standard test conditions required for thin him and crystalline silicon modules (IEC 1646 1996 and IEC 1215 1993). It is obvious that before nc-DSCs can be commercialized on a large scale, IEC 1646... 

Energy is consumed in the manufacture of solar modules. It has been estimated by NREL that for a crystalline silicon module, the payback period of energy is about 4 years. For an amorphous silicon module this period is currendy about 2 years, with the expectation that it will eventually be less than 1 year. 

Current production of solar cells is dominated by crystalline silicon modules however, due to the high refractive index of silicon, more than 30 percent of incident light is reflected back, which greatly reduces the conversion effi-... 

N. Stoddard, B. Wu, L. Maisano, R. Russel, J. Creager, R. Clark, J. Manuel Ferrandez, in 18th Workshop on Crystalline Silicon Solar Cells and Modules Materials and Processes, pp. 7-14, 2008, ed. by B.L. Sopiri... 

As the cost of the silicon wafer is about half the final cost of the solar cell module, the use of crystalline thin film on non-silicon low-cost substrate is of great interest. The main issues are the compatibility of the substrate with... 

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