Synthesis and Optical Properties of In2S3-Hosted Colloidal Zn–Cu–In–S Nanoplatelets

High-efficiency photoluminescence quaternary hexagon Zn–Cu–In–S (ZCIS) nanoplatelets (NPls) have been synthesized by a two-step cation exchange method, which starts with the In2S3 NPls followed by the addition of Cu and Zn. It is the first time that In2S3 NPls are used as templates to synthesize ZCIS NPls. In this paper, the reaction temperature of In2S3 is essential for the formation of NPls. The photoluminescence wavelength of NPls can be tuned by adjusting the temperature of Cu addition. To enhance the stability of the resulting NPls and to improve their optical properties, we introduced Zn2+ and obtained ZCIS NPls by cation exchange on the surface. It is worth noting that the obtained ZCIS NPls show a shorter fluorescence lifetime than other ternary copper sulfide-based NPls. This work provides a new way to synthesize high-efficiency, nontoxic, and no byproduct ZCIS NPls.