Silicon Nanocrystals for Superefficient Solar Cells

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• 	Synergy Siphon on 08/21/2007 at 5:17 AM
  Posts: 112 Avg Rating:	Wouldn't this be great to combine with other novel silicon technologies, such as Sliver Cells? Or silicon (amorphous) thinfilm maybe? Rate this comment: (Reply)

  • Re: Synergy cripdyke on 08/26/2007 at 3:53 AM

    Posts: 15 Avg Rating:

    I think that, frankly, you failed to understand the article. This tech uses silicon NANOcrystals. Thin films are only valuable because they use less of the  expensive pure silicon crystals grown to large sizes and thicknesses under exacting conditions. Nanocrystals are even smaller than thin film, which amounts to slicing the expensive crystals very thin so as to use less of an expensive ingredient and thus keep cost of manufacture lower than otherwise. Nanocrystals are in fact so much smaller as to make comparisons a joke, really. Large, pure crystals are not the raw material for nanocrystals. And the nanocrystals cannot be amorphous... because they are crystals. Now on the upside, this tech not only gains from the advantages of efficiency inherent in producing different numbers of electrons based on the amount of energy in the striking photon, but since it doesn't start out as a pure crystal -thick disk or thin film- a manufacturer does not incur the expense of paying for the expensive pure-silicon-crystal-growth processes. So, the "synergy" with these other techs is effectively already in this one: high efficiency from nano, low costs from avoiding using large amounts of large, pure crystals. And yet it is not synergy at all, nor is it something that we must research to apply. Nanocrystals are not merely thin, they are ridiculously small. "Nano" by definition generally refers to things that are no more than a tenth of a millionth of a meter (100 nanometers or 100nm) in at least 2 spacial dimensions. (Although some "nano" work is in the field of nanofilms that meet this requirement in only 1 dimension, thickness, and are designed to be spread over surfaces for much larger distances than 100nm, often even macroscopic distances.) For these crystals they meet the 100nm criterion in all 3 spacial dimensions. As well, it is impossible for a nanocrystal to be amorphous, in the sense of non-crystalline. If it's a nanocrystal, it's a crystal...just a small one. Hope that helps. Rate this comment: (Reply)

    • Re: Re: Synergy Siphon on 08/27/2007 at 3:59 PM

      Posts: 112 Avg Rating:

      Yes it does, thank you. Amorphous? What was I thinking, duh. Unless of course the nanocrystals were irradiated for long periods of time (but why would one do that?) The extreme size of the crystals actually sounds very problematic for mass production. How do you deposit these things onto anything adequately and homogeneously? And if that could be done, how do the crystals degrade over time in real world conditions? Rate this comment: (Reply)

      • 	Re: Re: Synergy atsilver on 09/20/2007 at 4:55 PM
        Posts: 1	I aggree with Siphon on this last point (his/her second paragraph) and hope to see a reply soon (from concept to lab to technology and from here to commercially available products there is also a long way, sometimes unable to be completed). And this is not a minor affair, nor a problem of correct understanding of the article, but a practical point of view. Rate this comment: (Reply)