B-Site Doping of Metal Halide Perovskite Nanoplatelets Influences Their Optical Properties

Metal halide perovskite nanoplatelets (NPls) have recently joined a rich family of 2D semiconductor nanomaterials. Quantum and dielectric confinement in these nanostructures endow them with useful optical properties, which include, but are not limited to, high linear and nonlinear absorption coefficients, narrow and tunable emission bands, and high photoluminescence quantum yield. These characteristics render perovskite NPls promising for applications in lighting, photodetection, nonlinear optics, and photocatalysis. Doping is a universal approach for tuning optical and electronic properties of semiconductor materials, and the B-site doping of perovskite NPls allows the further improvement and adjustment on demand of the above-mentioned optical properties and may result in the appearance of fundamentally new behavior through embedding optically active dopants. In this mini-review, the basic knowledge about perovskite NPls is shortly summarized in terms of their colloidal synthesis, and then the B-site doping of perovskite NPls is considered in terms of the existing approaches (in situ and post-synthetic doping) and its effect on the optical characteristics (doping with self-emitting ions such as Mn2+ and rare-earth elements; consequences for the nonlinear optical response).