Synthesis and Optical Properties of InS-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 InS NPls followed by the addition of Cu and Zn. It is the first time that InS NPls are used as templates to synthesize ZCIS NPls. In this paper, the reaction temperature of InS 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 Zn 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.