Thursday, September 22, 2016
In a discovery that could have profound implications for future energy policy, Columbia scientists have demonstrated it is possible to manufacture solar cells that are far more efficient than existing silicon energy cells by using a new kind of material, a development that could help reduce fossil fuel consumption.
The team, led by Xiaoyang Zhu, a professor of Chemistry at Columbia University, focused its efforts on a new class of solar cell ingredients known as Hybrid Organic Inorganic Preovskites (HOIPs). Their results, reported in the prestigious journal Science, also explain why these new materials are so much more efficient than traditional solar cells—solving a mystery that will likely prompt scientists and engineers to begin inventing new solar materials with similar properties in the years ahead.
“The need for renewable energy has motivated extensive research into solar cell technologies that are economically competitive with burning fossil fuel,” Zhu says. “Among the materials being explored for next generation solar cells, HOIPs have emerged a superstar. Until now no one has been able to explain why they work so well, and how much better we might make them. We now know it’s possible to make HOIP-based solar cells even more efficient than anyone thought possible.”
Solar cells are what turn sunlight into electricity. Also known as photovoltaic cells, these semiconductors are most frequently made from thin layers of silicon that transmit energy across its structure, turning it into DC current.
Silicon panels, which currently dominate the market for solar panels, must have a purity of 99.999 percent and are notoriously fragile and expensive to manufacture. Even a microscopic defect—such as misplaced, missing or extra ions—in this crystalline structure can exert a powerful pull on the charges the cells generate when they absorb sunlight, dissipating those charges before they can be transformed into electrical current.