Non-toxic alternative for next-generation solar cells

Researchers have demonstrated how a non-toxic alternative to lead could form the basis of next-generation solar cells. We're just scratching the surface of what these compounds can do. Robert Hoye The team of researchers, from the University of Cambridge and the United States, have used theoretical and experimental methods to show how bismuth - the so-called 'green element' which sits next to lead on the periodic table, could be used in low-cost solar cells. Their results , reported in the journal Advanced Materials , suggest that solar cells incorporating bismuth can replicate the properties that enable the exceptional properties of lead-based solar cells, but without the same toxicity concerns. Later calculations by another research group showed that bismuth-based cells can convert light into energy at efficiencies up to 22%, which is comparable to the most advanced solar cells currently on the market. Most of the solar cells which we see covering fields and rooftops are made from silicon. Although silicon is highly efficient at converting light into energy, it has a very low 'defect tolerance', meaning that the silicon needs to have very high levels of purity, making it energy-intensive to produce.