Highly fluorescent CsPbBr3/TiO2 core/shell perovskite nanocrystals with excellent stability

Abstract

AbstractThe poor stability of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals is the most impediment to its application in the field of photoelectrics. In this work, monodisperse CsPbBr3/TiO2 nanocrystals are successfully prepared by coating titanium precursor on the surface of colloidal CsPbBr3 nanocrystals at room temperature. The CsPbBr3/TiO2 nanocomposites exhibit excellent stability, remaining the identical particle size (9.2 nm), crystal structures and optical properties. Time-resolved photoluminescence decay shows that the lifetime of CsPbBr3/TiO2 nanocrystals is about 4.04 ns and keeps great stability after lasting two months in the air. Results show that the coating of TiO2 on CsPbBr3 NCs greatly suppressed the anion exchange and photodegradation, which are the main reasons for dramatically improving their chemical stability and photostability. The results provide an effective method to solve the stability problem of perovskite nanostructures and are expected to have a promising application in optoelectronic fieldsArticle highlights 1. Prepared the all-inorganic CsPbBr3/TiO2 core/shell perovskite nanocrystals by an easy method. 2. Explored its essences of PL and lifetime of the synthesized CsPbBr3/TiO2 perovskite nanocrystals. 3. CsPbBr3/TiO2 nanocrystals show the great thermal stability after the post-annealing. 4. The CsPbBr3/TiO2 nanocrystals have a high PLQY and have a promising application in solar cells.