If/when the market for PV gets bigger, they'll move to silicon production dedicated to PV cells where energy input is likely to be way smaller and prices will go down big time too (since they won't compete with silicon-gold-chips for this ressource anymore).

The problem is that chip production is so massively profitable that PV will have a hard time matching it, no matter how popular it becomes.

I'm not expecting PV to take off until/unless it starts using a less demanding technology. It really needs to drop maybe 90% of its current price to become a viable everyday power source - even assuming a significant drop in demand.