It reminds me of howls moving castle <| sep |> Not happening . Tin perovskites have crap efficiency this one being , and further crap stability . In this paper they showed CsSnI 3 being stable , but still with an efficiency of 4 % this is purely academic . What ' ll likely happen is a mixture of Snx Pby perovskites with some mixed halide . Finally , to people worrying about lead in their solar cells , don ' t . It ' s a small quantity of lead , and there ' s a capping layer on the solar cell . Think about how we have Arsenic in your computer chips , why is lead that much worse ? Edit More on the toxicity of Pb vs Sn in perovskitesIn conclusion , the environmental impact of PbI 2 and SnI 2 , representing the main degradation products of the corresponding organometal halide perovskite solar cells , was tested by means of the model organism zebrafish Danio rerio according to the ZFET . At equal concentration for both compounds , a higher lethal response was found in the embryos exposed to SnI 2 than for PbI 2 . Furthermore , it could be revealed that lethality rates and morphological defects of SnI 2 treated embryos are not due to the presence of the heavy metal , but rather due to reduced pH value . This is explained by the fact that SnI 2 is a highly unstable product in ambient atmosphere , causing immediate decomposition into HI the acidifier , along with toxicologically inactive oxygenated Sn precipitates . Upon exposure to the Pb counterpart , a combined effect of the heavy metal itself along with the reduced pH is observed , as evidenced by the complex multiphasic appearance of the morphological record , where the presence of mainly PbOHI precipitate was found , along with smaller amounts of HI . Since both Sn and Pb are present here as inorganic compounds , it must be noted that their uptake is much lower in comparison to analogous organic molecules as in , for example , tetrabutyllead in leaded gasoline or tributyltins in industrial biocides Nevertheless , the release of HI introduces a new perspective in the possible routes of toxicity . Notably , the strong acidification induced by the SnI 2 is found to be more harmful than the combined effect of milder acidification and the expected Pb intoxication induced by PbI 2 . These results challenge the current view in solar cell development , where Snbased perovskites are regularly put forward as the nontoxic alternative of Pbbased ones . This leads to the recommendation that the enthusiasm towards the purported environmental friendliness of Snbased perovskites compared to Pbbased ones should be approached with great caution .