From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Wed Dec 25 2002 - 20:05:03 MST
On Wed, 25 Dec 2002, Jeff Davis wrote:
> Silicon chips require single crystal silicon, right?
Yep.
> Fully two-thirds of the material was ground away!
Maybe not so much with Si, which I believe may be a bit
stronger than GaAs.
But Si is moving in the direction of Si on Al2O3 so
things are changing anyway. Al2O3 is probably stronger
so the slices can be even thinner.
> Or, why is not amorphous silicon made single crystal by some such
> similar process?
If there were an easy way to do this I think it would have
been found by now. Because Si based solar cells are a lot
more efficient if made out of single crystal Si compared with
amorphous Si. Something like 20+% vs. < 10%.
I suspect it is because to recrystallize amorphous Si one needs
to have an extremely uniform heating and cooling process moving
as a "wave-front" across the entire surface of the Si and
nobody has figured out how to do that yet. Or it may require
so much energy (say if you are using laser heating) that it is
prohibitively expensive.
My 2 cents.
Robert
This archive was generated by hypermail 2.1.5 : Wed Jan 15 2003 - 17:58:53 MST