Facile synthesis and optical study of organic-inorganic lead bromide perovskite-clay (kaolinite, montmorillonite, and halloysite) composites

The organic-inorganic hybrid perovskite methylammonium lead bromide nanocrystals are an important class of light-emitting materials. However, their poor stability under humid conditions hampers their practical applications. Herein, for the first time, MAPbBr₃ NCs have been successfully assembled with various clays, such as kaolinite, montmorillonite, and halloysite for synthesizing MAPbBr₃@clay composites. The bare MAPbBr₃ NCs and all the synthesized MAPbBr₃@clay composites show green emission ranging from 531 to 540 nm and an average lifetime spanning between 0.91 and 1.03 ns. These composite materials offer improved thermal stability up to 250 °C and luminescence properties under humid conditions for more than one month. These materials open up a new insight into obtaining stable nanocrystals with natural clay minerals.