While research continues to move perovskite solar technology toward commercialization, scientists at the National Renewable Energy Laboratory (NREL) are investigating how to manufacture them with human health in mind.   Newly published research points to the safest choices for solvents needed to make perovskite solar cells.    Unlike silicon solar panels, which require an industrial process, perovskite solar panels can be made using chemicals and produced using a roll-to-roll printing me...