Monodisperse CuInS2/CdS and CuInZnS2/CdS Core–Shell Nanorods with a Strong Near‐Infrared Emission

Given the ubiquitous examples of semiconductor nanorods synthesis, CuInS2‐based anisotropic heterostructures still lag behind in terms of shape/optical properties control. Here, core/shell CuInS2/CdS dot‐in‐rod nanoheterostructures which exhibit high degree of the morphology control, and a strong emission in the near‐infrared range of 700–900 nm, are realized. The authors made use of the seeded growth approach utilizing wurtzite CuInS2 quantum dots as seeds, which allows for tuning the dimension of the resulting core/shell nanorods, including the core size and the shell thickness. Time‐dependent photoluminescence studies reveal slowing down of the recombination rate with increasing thickness of the shell, which is characteristic for the quasi‐type II heterostructure. Alloying of the CuInS2 cores with Zn does not perturb the shell growth process, but enables improvement of the photoluminescence quantum yield of the resulting core/shell CuInZnS2/CdS nanorods to 45%, as compared to ≈30% for CuInS2/CdS nanorods.