A 'raincoat' protects lead-free solar cells from the elements

Executive Briefing & Key Highlights

One drawback of most solar cells made with efficiency-boosting perovskite is the presence of hazardous lead in the materials that turn sunlight into electricity. Next-generation solar cells made with the most promising lead-free replacement—nontoxic tin perovskite—have had their own major weakness: They don't hold up against the elements.