Beyond Colloidal Cesium Lead Halide Perovskite Nanocrystals: Analogous Metal Halides and Doping

Colloidal CsPbX3 (X = Cl, Br, I) nanocrystals (NCs) are being explored extensively as an interesting variety of defect-tolerant materials, wherein high efficiencies of optical and optoelectronic processes can be achieved even in the presence of surface defects. This defect-tolerant nature arises mainly because of the unique electronic band structure of these perovskites. Consequently, synthesis and exploration of other metal halide {CsSnX3, Cs2SnX6, and (CH3)3Bi2X9} NCs with electronic band structure similar to that of CsPbX3 perovskite have begun with high promise. Another initiative to tailor the properties is the doping of metal ions (Mn2+, Zn2+, Cd2+, Sn2+, and Bi3+) into the lattice of CsPbX3 NCs. Furthermore, nanocomposites of CsPbX3–metal and CsPbX3–dielectric layer–metal have been attempted. Here we discuss the recent progress in the research of these colloidal metal halide NCs that are either analogous to CsPbX3 perovskites or derivatives of CsPbX3 perovskites.