Experimentally CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe are important materials as quantum dots for PL-related and other optoelectronic applications.GaN, GaAs, InAs, InSe etc too can be chosen.
Some perovskite quantum dots are also useful specially for DFT-based jobs. Because perovskite unit cells are simple and the associated computational cost is less compared to many other crystal structures.