Colloidal lead halide perovskite nanocrystals: synthesis, optical properties and applications

Lead halide perovskite nanocrystals (NCs) are receiving a lot of attention nowadays, due to their exceptionally high photoluminescence quantum yields reaching almost 100% and tunability of their optical band gap over the entire visible spectral range by modifying composition or dimensionality/size. We review recent developments in the direct synthesis and ion exchange-based reactions, leading to hybrid organic–inorganic (CH3NH3PbX3) and all-inorganic (CsPbX3) lead halide (X=Cl, Br, I) perovskite NCs, and consider their optical properties related to quantum confinement effects, single emission spectroscopy and lasing. We summarize recent developments on perovskite NCs employed as an active material in several applications such as light-emitting devices, solar cells and photodetectors, and provide a critical outlook into the existing and future challenges. Although research into perovskite nanocrystals is still in its infancy, they are expected to be major players in future nanoscience. Lead halide perovskite nanocrystals are attracting much interest because their quantum yields for photoluminescence are approaching 100% and their optical band gap can be tuned over the entire visible wavelength region – properties that make them promising for use in lasers, light-emitting diodes (LEDs) and solar cells. Andrey Rogach of City University of Hong Kong and co-workers review the latest developments in the synthesis (of both hybrid organic-inorganic and all-inorganic nanocrystals), optical properties (quantum confinement effects, single particle emission and lasing studies) and applications (LEDs, solar cells and photodiodes) of these materials. They outline some of the many remaining challenges, but state their confidence that these should soon be overcome. This review summarizes recent developments in the direct synthesis and ion exchange-based reactions leading to hybrid organic–inorganic and all-inorganic lead halide perovskite nanocrystals. Optical properties related to quantum confinement effects, single emission spectroscopy and lasing are considered. Perovskite nanocrystals have been employed as an active material in several applications such as light-emitting devices, solar cells and photodetectors.