CdTe panels are actually made of a cadmium telluride film on glass, rather than silicon; the patent http://www.patentstorm.us/patents/5393675-claims.html (by a person who doesn't seem to be involved with First Solar, so the technology may have changed) suggests that the active film is only about a micron thick, and protected on both sides by other cadmium compounds. This isn't a dopant issue.
First Solar seem to be keeping the CdTe step of their work as a trade secret, and are patenting mechanical parts of the apparatus, various laser-cutting processes, chemistry for CVD of materials other than cadmium and tellurium, and a remarkably obvious patent on crushing defective cells and dissolving them in acid before recovering the Cd and Te by electrolysis.
On the whole I'd rather not lick cadmium chloride, since it's reasonably soluble and reasonably toxic. I'd expect any working system to have the CdTe layer pretty well encapsulated.
Tom,
Thank you, a sane person on this thread. I worked for First Solar. 2 years in R & D. One of my tasks was to load the system with cad,tellurinium and sulfide. Chloride was down stream from me...another of my tasks was to measure the surface profile, big bad with that one. Previous to that, I was in the re-cycling dept. I assure U, nothing in that place was recycled...you don't recycle CdTe, you stash it...they still have the cad I wiped off of every panel that didn't make it to Shipping and receiving. Very hazardous, they don't have enough money to throw that sh#t out. Ask yourself this, why bother with the wiping it off of the glass? Cause it's Hazardous!!! Sheesh!!! Plus, it's easier to store. In drums. That are still there. The thing is, if they ever move from that building, the cad's going with 'em. Gee, why's that if it is so friendly?
Jeff
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CdTe panels are actually made of a cadmium telluride film on glass, rather than silicon; the patent http://www.patentstorm.us/patents/5393675-claims.html (by a person who doesn't seem to be involved with First Solar, so the technology may have changed) suggests that the active film is only about a micron thick, and protected on both sides by other cadmium compounds. This isn't a dopant issue.
First Solar seem to be keeping the CdTe step of their work as a trade secret, and are patenting mechanical parts of the apparatus, various laser-cutting processes, chemistry for CVD of materials other than cadmium and tellurium, and a remarkably obvious patent on crushing defective cells and dissolving them in acid before recovering the Cd and Te by electrolysis.
On the whole I'd rather not lick cadmium chloride, since it's reasonably soluble and reasonably toxic. I'd expect any working system to have the CdTe layer pretty well encapsulated.
Tom,
Thank you, a sane person on this thread. I worked for First Solar. 2 years in R & D. One of my tasks was to load the system with cad,tellurinium and sulfide. Chloride was down stream from me...another of my tasks was to measure the surface profile, big bad with that one. Previous to that, I was in the re-cycling dept. I assure U, nothing in that place was recycled...you don't recycle CdTe, you stash it...they still have the cad I wiped off of every panel that didn't make it to Shipping and receiving. Very hazardous, they don't have enough money to throw that sh#t out. Ask yourself this, why bother with the wiping it off of the glass? Cause it's Hazardous!!! Sheesh!!! Plus, it's easier to store. In drums. That are still there. The thing is, if they ever move from that building, the cad's going with 'em. Gee, why's that if it is so friendly?
Jeff