Does anyone know if we’ll be able to laser-cut solar cells with the Glowforge?
Probably not, I would guess. Silicon has a ridiculous melting temp. Although it doesn’t conduct heat as well as metal, so if the cell is thin enough. But also brittle, so the heat might lead to unwanted fractures. Anyone tried this with a GF-class laser?
Even if it can cut them, doing so may make them stop working, since the back side of a standard solar cell has the conductors and wiring that carries the electrons (aka electricity) out of the cell. I suspect if you are great with a soldering iron and have the skills necessary, you could reinstate the necessary conductivity manually after the shaping though.
Silicon and copper are natural enemies of CO2 lasers In fact, silicon is used in lots of CO2 laser mirrors since it is incredibly reflective at that wavelength.
I have to wonder what detriment copper presents?
Thank you @aeva.
I think it is the same deal, copper also reflects at CO2 laser wavelength(s).
Yep! Many copper-etching laser systems (like LPKF) use a Nd:YAG at 1.064um vs a CO2 laser’s wavelength of 10.6um. 9 micrometers makes all the difference
Electrical engineering and physics!
Thanks guys, still new to lasers and figured I’d ask here before hitting the Google. Cheers.
When you get close enough these two[quote=“printolaser, post:8, topic:2111”]
Electrical engineering and physics!
start to look pretty similar.
Yes, should have phrased it “…and underlying physics”
Nah, EE is just Physics with too many simplifying assumptions
For those who work with light a bit more often:
1064nm for Nd (with some variation depending on the crystal used)
10,600 nm for CO2 (and you can tune that wavelength a little bit)
Bumping this thread now that GF’s exist! What are the safety concerns? Has anyone here tried this?
I’m hoping to cut up cells like this:
Amazon Solar Cells - 100pcs
Not sure why anyone would want to cut the cells. If you want smaller, why not buy smaller ?
I need tiny ones, and have just bought 50, 5mm x 5mm for micro led displays. Not sure if it’s going to work, but that’s what makes life exciting !
EDIT ~$10 on ebay
this post from earlier in the thread should answer your question. i doubt anyone has tried it.
Because I want to cut them in interesting shapes! I want the solar cell to be the front surface, and hopefully power a tiny LED beneath.
Re: Silicon - sounds chemically okay, just not likely to work. Is it safe to try?
With tape on it, would I need to worry about a direct reflection, or would it all get scattered enough? Worst-case it just doesn’t cut, or could I break the GF?
I honestly can’t think of any reason not to try.
Perhaps for the very first attempt, just treat it like glass, with masking on, to see if you get any sort of mark on the surface of the cell.
Since cutting or scoring requires that the material absorb the laser energy, and since silicon is a good reflector of light at CO2 wavelengths, I doubt it would work.
Worst case you reflect the laser right back into the head and melt something.
I won’t be trying on my machine.
Not what I thought, just the reverse in fact.
So I googled IR transmission of Silica.
For most IR applications in the wavelength range from 780 - 3600 nm synthetic fused silica is the material of choice.
I expect the surface of solar cells to be crystalline, rather than fused, but I don’t think of them as good reflectors.
Maybe I am misunderstanding you but Silica (SiO2) and Silicon (elemental Si) have very different properties. Solar cells are Silicon and I think that even if they are made from amorphous material they are still cut and polished (at least to some degree). Regardless of surface texture the Silicon will still reflect the laser although the reflected beam might be diffused and not very melty.