Advances in Quantum‐Confined Perovskite Nanocrystals for Optoelectronics

Metal halide perovskites have emerged as a promising new class of layered semiconductor material for light‐emitting and photovoltaic applications owing to their outstanding optical and optoelectronic properties. In nanocrystalline form, these layered perovskites exhibit extremely high photoluminescence quantum yields (PLQYs) and show quantum confinement effects analogous to conventional semiconductors when their dimensions are reduced to sizes comparable to their respective exciton Bohr radii. The reduction in size leads to strongly blueshifted photoluminescence and large exciton binding energies up to several hundreds of meV. This not only makes them interesting for optoelectronic devices, but also enables complex architectures based on cascaded energy transfer. Here, an overview of the current state‐of‐the‐art of quantum confinement effects in perovskite nanocrystals is provided, with a focus on synthetic strategies and resulting optical properties, characterization methods, and emerging applications.