More efficient perovskite solar cell

From left Leiwei Zeng, Zaiwei Wang and Hao Chen show off samples of triple-junction perovskite solar cells that boast record gains in efficiency (photo by Tyler Irving) - A team of researchers from the University of Toronto has created a triple-junction perovskite solar cell with record efficiency by overcoming a key limitation of previous designs. The prototype represents a significant advance in the development of low-cost alternatives to silicon-based solar cells, which are the current industry standard. "In addition to lower manufacturing cost, perovskites offer us the ability to stack multiple layers of light-absorbing materials on top of each other, and even on top of traditional silicon cells," says Professor Ted Sargent , who recently joined the department of chemistry and the department of electrical and computer engineering at Northwestern University but maintains his lab at University of Toronto's Faculty of Applied Science & Engineering. "In this work, we used rational design to address a critical challenge that can arise in this multi-layered paradigm, improving both efficiency and durability." Today's solar cells are made from a single wafer of ultra-pure silicon, which is energy-intensive to produce. By contrast, perovskite solar cells are made using perovskite polycrystalline films that are coated onto surfaces with low-cost, solution-processing techniques similar to those used in the printing industry. By varying the composition of the perovskite crystals within these films, each layer can be "tuned" to absorb different wavelengths of light, making efficient use of the entire solar spectrum.