State of the art and prospects of metal halide perovskite core@shell nanocrystals and nanocomposites

Metal halide perovskite nanocrystals (NCs) have shown tremendous progress because of their unique inherent photophysical properties, which driven them for potential application in the fields of light emitting diodes, solar cells, photodetectors, lasing, bioimaging, and so on. However, the instability of perovskite NCs in ambient atmosphere, especially in presence of moisture, is one of the major challenges that need to overcome before their commercial applications. The stability of perovskites can be improved by forming a protective shell material that not only prevents them from further degradation but also generates new materials properties. Core@shell semiconducting nanostructures have attracted immense attention worldwide because of their ability to tune optical properties by varying their size and composition. This core@shell NCs synthesis is known to be a unique technique that further improves the crystal structure and photostability. It has been anticipated that the advantages of these NCs can be eventually realized in various optoelectronic and bioimaging applications. This review article provides a brief description of a recent progress report on metal halide perovskite core@shell NCs with different types of shelling materials, such as metal oxides, high bandgap metal halide perovskites, metalchalcogenides, metal-organic frameworks, and polymers. In addition, we have also discussed a new type of core@shell nanomaterials with metal chalcogenides core and metal halide perovskite shell. This review mainly focuses on the up-to-date analysis of various types of core@shell NCs growth processes, and their associated photophysical properties, especially their emission properties, and corresponding stability. Finally, we emphasize some of the major challenges facing during the synthesis of core@shell NCs, and future aspects for further development in different optoelectronic and bioimaging applications. (c) 2021 Elsevier Ltd. All rights reserved.