Unleashing perovskites' potential for solar cells

[OKIsItJustMe]

https://news.mit.edu/2019/perovskites-microstructure-solar-cells-0207

Unleashing perovskites’ potential for solar cells

New results show how varying the recipe could bring these materials closer to commercialization.

David L. Chandler | MIT News Office
February 7, 2019

Perovskites — a broad category of compounds that share a certain crystal structure — 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.

Conventional solar cells made of silicon must be processed at temperatures above 1,400 degrees Celsius, using expensive equipment that limits their potential for production scaleup. In contrast, perovskites can be processed in a liquid solution at temperatures as low as 100 degrees, using inexpensive equipment. What’s more, perovskites can be deposited on a variety of substrates, including flexible plastics, enabling a variety of new uses that would be impossible with thicker, stiffer silicon wafers.

Now, researchers have been able to decipher a key aspect of the behavior of perovskites made with different formulations: With certain additives there is a kind of “sweet spot” where greater amounts will enhance performance and beyond which further amounts begin to degrade it. The findings are detailed this week in the journal Science, in a paper by former MIT postdoc Juan-Pablo Correa-Baena, MIT professors Tonio Buonassisi and Moungi Bawendi, and 18 others at MIT, the University of California at San Diego, and other institutions.

Perovskites are a family of compounds that share a three-part crystal structure. Each part can be made from any of a number of different elements or compounds — leading to a very broad range of possible formulations. Buonassisi compares designing a new perovskite to ordering from a menu, picking one (or more) from each of column A, column B, and (by convention) column X. “You can mix and match,” he says, but until now all the variations could only be studied by trial and error, since researchers had no basic understanding of what was going on in the material.

…

http://dx.doi.org/10.1126/science.aah5065

[NNadir]

1. Almost all of the "perovskites" investigated for the useless solar industry are lead compounds.

The environmental consequences of solar energy which have been the subject of so much waste of resources would be infinitely worse if this perovskite nonsense is allowed to proceed.

Imagine if all those solar cells on the roofs of California houses that burned recently - in part because the solar fantasy has proved completely useless in addressing climate change - has been cesium lead iodate perovskites.

This is absolutely nothing to applaud. On the contrary, it is something to fear, as one fears fear and ignorance.