Ligands Induced the Growth of Colloidal AgInS 2 Nanoparticles with Tuned Structure and Photoluminescence Property

Understanding the growth mechanism of AgInS nanoparticles could benefit the designed growth of I-III-VI nanomaterials and their applications in photonics, optoelectronics, etc. Herein, using tris(dibutyldithiocarbamate) indium(III) [In((C H ) NCS ) ] ([InR ]) and dibutyldithiocarbamate silver(I) [Ag((C H ) NCS )] ([AgR]) precursors, AgInS -based nanoparticles with different structures have been synthesized in a controlled manner through a one-pot approach via different growth mechanisms in 1-dodecanethiol (DDT) and oleylamine (OLA), respectively. The DDT and OLA could participate in the decomposition of precursors; thus, the [AgR]/DDT, [InR ]/DDT, [AgR]/OLA, and [InR ]/OLA were used herein to describe the decomposition steps. In DDT, the decomposition activity of [AgR]/DDT was much higher than that of [InR ]/DDT; thus, the sequential decomposition of [AgR]/DDT and [InR ]/DDT led to the formation of the Ag S nanoparticles intermediate first, which then reacted with [InR ]/DDT to form metastable -AgInS nanoparticles via the cation exchange and alloy process, and finally evolved into -AgInS @InS core@shell nanoparticles, while in OLA, the decomposition activity of [AgR]/OLA was slightly higher than that of [InR ]/OLA. Thus, the quasi-co-decomposition of [AgR]/OLA and [InR ]/OLA led to the formation of Ag-rich Ag-In-S amorphous nanoparticles intermediate first and then quickly evolved into stable -AgInS /InS nanoparticles. In addition, the photoluminescence quantum yield (PLQY) of -AgInS /InS nanoparticles was higher than that of -AgInS @InS nanoparticles.