Solar panels use cadmium and lead in trace quantities that makes recycling certain parts of solar panels unprofitable. I can easily see this being like plastics all over again.
Cadmium is not used by Si cells, which comprise 95% of the market. Lead has been used in back contact sheets but is being phased out. Heavy metals are not necessary for solar.
https://www.forbes.com/sites/forbes-personal-shopper/2021/01...