Exceptionally Stable CH₃NH₃PbI₃ Films in Moderate Humid Environmental Condition

Abstract

<b>An unprecedentedly stable CH₃NH₃PbI₃ film synthesized by a modified chemical vapor transport method</b> is demonstrated. The results show that the crystal structure, light absorption, and device efficiency do not degrade after storing for 100 d in air with 40% relative humidity, while the conventional solution-processed perovskites are usually stable for less than 20 d in similar conditions.