For the production of solar-grade feedstock, WACKER has optimized its production process taking into account the requirements ofthe solar industry for lower cost at maximum quality level (Hesse, 2009, Industry Announcements (n. d.), Rogol et al., 2009). • The deposition process was modified for maximum deposition rate. The resultant SG morphology does not impact the […]
Category: Advances in Photovoltaics:. Volume
Which polysilicon characteristics can provide the right feedstock?
A loss analysis of advanced cells supports the vital relevance of high lifetime (Cousins et al., 2006). Several reviews describe the corresponding parameters of crystalline SG-Si for high-efficiency cells (Geerligs et al., 2011; Glunz, 2007) . For lower efficiencies, the corresponding parameters of SG-Si feedstock were reviewed by Pizzini (2009, 2010) and Pizzini et al. […]
ACCOMMODATION TO PV REQUIREMENTS
Exploring alternative technologies of the “Silane Route,” dozens of different processes have been studied for many years, particularly, for the production of SG-Si (Ceccaroli and Lohne, 2006; Rogers, 1990). Regarding metallic impurities, the purity of SG-Si is approximately 6 orders of magnitude higher than the metallic purity of a typical MG-Si. Referring to Sections 4.2—4.5, […]
Solar PVs is a source of renewable energy with the highest power density of renewable energy sources. As such, solar PV electricity should be a product of a clean industry, per definitionem. Solar PVs is mainly based on HVM of polysilicon, and like all industrial processes, it interferes with the environment in different ways. Fortunately, […]
Time to market
Very important is the length of the period that is necessary to develop new technologies to an economical HVM production scale. Beginning with the first working concept and developing it over lab and pilot scale to HVM takes at least 10 years. This is a very long time frame compared to actual extremely dynamic growth […]
Why do silicon and the Siemens process, i. e. the "silane route" dominate the solar feedstock industry?
Although researchers of alternative PV materials disclosed that, based on the lifetime energy output, inexpensive thin film of, for example, iron sulfide FeS2 could be more promising than high-efficiency silicon cells (Wadia et al., 2009) and the future of the Siemens process has been regularly questioned (Kohler et al., 2011; Xiao-gang and Li-rong, Dec, 2008), […]
Arguments regarding "high energy/high cost" rating (Hesse et al., 2008a)
Some environmentally concerned scholars regarded the production of solar – grade feedstock via gas phase deposition as being “too costly” because of the “high” energy consumption of the deposition process, and that purification of silicon via metallurgical processes, that is, different melting and crystallizaton steps, slag refining, treatment with different gases, etc. is much less […]
Comparison of HVM technologies
Manufacturing solar silicon consists of two basic processes: i. Direct chlorination of MG-Si with STC recycling in a separate thermal conversion or hydrochlorination of MG-Si with STC recycling in the TCS synthesis to precursor silanes and ii. CVD of the precursor silanes. For the CVD process, three basic procedures have been developed: i. deposition ofTCS […]