5 ms·
"Silicon solar cells do not contain toxic compounds. " This is absolutely untrue. The silicon is just the starting base, you still need to dope the cells, ofte
by lightedman 4y ago
"Silicon solar cells do not contain toxic compounds. "
This is absolutely untrue. The silicon is just the starting base, you still need to dope the cells, often with an arsenic compound (Indium-Gallium Arsenide, Gallium Arsenide, etc.)
In the EU and California, solar panels are exempt from RoHS requirements.
I used to manufacture solar panels for Sunspark Technology in California. You can't get the same kind of conductivity using tin bus ribbon without sacrificing usable cell area, as you need a wider, flat strip of tin, compared to lead. The newest "invisible bus bar" panels are using silver wire. These cells, when I worked there pre-COVID, were dumping ~11A at full light exposure. The inter-string bus bars were lead-coated copper, as were the string to junction box interconnect ribbons. 60/40 was used in the junction box. We manufactured panels for everyone, including Jinko, that behemoth of a solar corporation.
Solar panels very often have toxic stuff everywhere.
- philipkglass 4y agoIndium gallium arsenide and gallium arsenide are compound semiconductors that are far too expensive for use in mass market panels. They are used as cells or components of multi-junction cells for satellites and a few other high value applications. Commercial silicon cells are doped with phosphorus and boron or gallium. On further reading I find that you are correct about RoHS exemptions for lead in solar modules: https://www.pv-magazine.com/2019/12/07/the-weekend-read-taking-the-lead/ https://www.pv-magazine.com/2019/12/07/the-weekend-read-taki... I appreciate the correction.
- tedk-42 4y agoThis back and forth made my day :)
- lightedman 4y agoCommercial cells doped with boron are meant for use in low-light applications due to higher efficiencies in lower/diffuse light, and are not very suited to direct-sunlight applications due to the tradeoff. Indium and Gallium-doped single-crystal silicon still wins in efficiency. Phosphorous I have not seen in any of the roughly 5 million cells I've handled as part of QC. I've heard of nanoparticles of phosphorous helping perovskite-based cells, but that's about it. I've never handled one in commercial production.