Perovskite chemical gardens: highly fluorescent microtubes from self-assembly and ion exchange

Abstract

We report the shape-preserving conversion of self-assembled CaCO₃ microtubes to PbCO₃ and MAPbBr₃ perovskite. The first step induces the growth of cerussite needles on the outer surface. When further converted, these hedgehog-like structures become fluorescent. Additional spatial control of the process yields Janus tubes of CaCO₃ and perovskite segments.