Perovskite solar panels

These are a type of photovoltaics. See the Wikipedia article for technical details.

Lead toxicity

Likely problem

The best-performing perovskites are lead-based. This probably wouldn't be an issue for small electronics managed properly, but could maybe pose a major environmental hazard if every rooftop were covered in these panels (which is roughly what would be needed to produce generate enough energy to replace all fossil fuels).

Mineral scarcity

Likely problem

There are a few alternatives to lead-based perovskites - most involve tin and/or cesium, which are rarer metals than lead. If the goal is to replace most fossil fuels, resources might be far too scarce.^{[QUANTIFICATION needed]}

Efficiency

Good

The best achievable efficiency is 33%, although this is difficult and expensive. 20% efficiency is probably a more realistic expectation,^{[RESEARCH needed]} which would be comparable to other high-performing solar panels on the market (most of which are also mineral-intensive in other ways).