Scientists find safer, greener way to make solar cells Greener solvent means safer way to make solar cells. Credit: SPECIFIC/Swansea University. Scientists at SPECIFIC Innovation and Knowledge Centre, Swansea University, have found a way to replace the toxic, unsustainable solvents currently needed to make the next generation of solar technology. Printed carbon perovskite solar cells have been described as a likely front runner to the market because they are extremely efficient at converting light to electricity, cheap and easy to make. A major barrier to the large-scale manufacture and commercialization of these cells is the solvents used to control crystallisation of the perovskite during fabrication.