Key Words:Cesium iodide;Cesium - Hydrogen bonds - Moisture - Perovskite;Healing process - Large-scale fabrication - Liquid Phase - Moisture stability - Non-polar - Perovskite films - Preferred orientations

Abstract:We report here the discovery of a fancy interaction between cesium iodide (CsI) and methylamine (CH<inf>3</inf>NH<inf>2</inf>) due to the presence of the hydrogen bond. The formed CsI·xCH<inf>3</inf>NH<inf>2</inf>is a liquid phase, which facilitates the large scale fabrication of highly uniform cesium-containing perovskite films with strong (110) preferred orientation by the CH<inf>3</inf>NH<inf>2</inf>gas healing process. With this method, at most 10% nonpolar Cs cations could fully dope into the crystal lattice and extremely enhance the interaction of the inorganic framework with a more symmetrical PbI<inf>6</inf>octahedron, resulting in obvious improvement in moisture stability under continuous illumination. © The Royal Society of Chemistry.

Volume:5

Issue:10

Translation or Not:no