Mapping the behaviour of solar cell material

Perovskite is a promising material for solar cells and could play a part in the energy transition. One of the obstacles to successful implementation is that the mobile ions in perovskite slowly corrode the material from within. 

Mobile ions are difficult to study. Inspired by the behaviour of freezing water, the research team introduced a new and intuitive approach. When water freezes, it stops moving. In a similar way, the movement of mobile ions ceases in a cooling solar cell. 

Researcher Moritz Schmidt: “Before it freezes, we push all the ions to one side of the solar cell. As the material heats up, the ions start to flow again, just like water in melting ice. Because the ions are charged, a measurable voltage is generated.” The new method thus shows how many mobile ions there are and how strong the voltage between them is.