BISMUTH could offer a non-toxic alternative to lead in next-generation perovskite solar cells, according to researchers at the University of Cambridge, UK.
Conventional silicon solar cells require extremely pure, defect-free silicon, which makes them energy-intensive to produce. Alternative materials like perovskite do not require such high purity levels, making them cheaper to produce. However, one of the sticking points has been the need to use lead, which is integral to their functional structure. The team at Cambridge, led by materials scientist Robert Hoye, sought to determine why perovskite cells are so defect tolerant, and subsequently find ways to replace lead with non-toxic alternatives. The researchers worked with colleagues at MIT, the National Renewable Energy Laboratory and Colorado School of Mines in the US, and identified bismuth, which sits next to lead in the periodic table, as a possibility.