MIT News February 7, 2019
Perovskites have attracted a great deal of attention as potential new solar-cell materials because of their low cost, flexibility, and relatively easy manufacturing process. But much remains unknown about the details of their structure and the effects of substituting different metals or other elements within the material. A team of researchers in the US (MIT, UC San Diego, Georgia Institute of Technology, Purdue University, Argonne National Laboratory) found that adding these alkali metals, such as cesium or rubidium, to the perovskite compound helps some of the other constituents to mix together more smoothly making it conduct electricity more easily and thus improving its efficiency as a solar cell. But, they found, that beyond a certain concentration, the added metals clump together, forming regions that interfere with the material’s conductivity and partly counteract the initial advantage. In between, for any given formulation of these complex compounds, is the sweet spot that provides the best performance…read more. TECHNICAL ARTICLE
Solar cells made of perovskite have great promise, in part because they can easily be made on flexible substrates, like this experimental cell. Image: Ken Richardson