Selenium Wire or Foil for Photoconductivity Demonstration

Why not use copper foil for a demo? hold the foil in a flame until nicely oxidized, then clean a small area for electrode 1, apply electrode 2 to the oxide, voila, a photo diode.

I am trying to reconstruct Willoughby's discovery. Cu2O will come further along with Grondahl and Ohl.

Thanks much, Ed V.

I was hoping for smaller amounts than they offer.

Thanks, Ed V.

You could probably find an old selenium rectifier (maybe e-bay) and disassemble it.

I have found what I think is a selenium-coated sheet of metal on the drum of a big old (80s) IBM laser printer / photocopier (it was a huge machine and had a rolled-up store of drum-coating inside the drum and an empty spool, and every so often it would change its own drum coating). I don't know if they still use selenium these days or if it is now silicon or something else, but I bet you could find a discarded laser printer or a cartridge containing the drum (sometimes in the toner cartridge) at a dump, or in a skip or similar, especially now that the new cartridges seem to cost more than the printers in some cases.

Chris