I'm semithrilled to learn that TEOS is hotseller on eBay.. (BC intrusive thoughts of inhaling glass)

Same reaction to purportedly sub-$30/300degC homemade solar cells (BC lead poisoning) inclusive of equipment

https://youtu.be/3ghatCS0_HY <-- another PhD

https://pubs.rsc.org/ta/article-abstract/5/37/19972/587815/H...

(Somewhat more expensive, though more edible ingredients)

https://www.semiconductor.diy/guides/microwave-solar-panels/