Why Is Making Epitaxially Grown All Inorganic Perovskite–Chalcogenide Nanocrystal Heterostructures Challenging? Some Facts and Some Strategies

Abstract

Nanocrystal heterostructures are one of the frontline energy materials widely known for enhancing the rate of photocatalysis and tuning optical properties and are also used in photovoltaics. These nanostructures where two crystalline nanomaterials are placed together in a single building block and share lattices are extensively studied for chalcogenide semiconductors and metal oxides but limited for recently emerged perovskite nanocrystals. Due to differences in the crystal bonding nature, interface chemistry, and also the formation mechanism, some constraints are present in designing common reaction pathways for the simultaneous formation of perovskites and chalcogenides or similar nanocrystals sharing common lattice planes. Hence, more fundamental understanding of both nucleation and growth of both materials is required for inducing heteronucleations of one on the surface of another. Literature reports also revealed that epitaxial growth of lead halide perovskites with nonhalide or chalcogenide colloidal 0D nanocrystals could not be established yet. Hence, the field remains challenging, and more investigations on both experimental as well as theoretical studies are timely required. Keeping these in mind, in this perspective the state-of-the-art issues related to the formation of all inorganic halides and nonhalide heterostructures formed with epitaxial relations are discussed. At the beginning, the chemistry of these nanocrystals with similarities and dissimilarities in their nature and examples of different heterostructures are summarized, and then, different synthetic possibilities for overtaking the hurdles and designing such heterostructures are proposed.