Ligands Induced\nthe Growth of Colloidal AgInS<sub>2</sub> Nanoparticles with Tuned\nStructure and Photoluminescence\nProperty

Understanding the growth mechanism of AgInS<sub>2</sub> nanoparticles\ncould benefit the designed growth of I–III–VI<sub>2</sub> nanomaterials and their applications in photonics, optoelectronics,\netc. Herein, using tris(dibutyldithiocarbamate) indium(III) [In((C<sub>4</sub>H<sub>9</sub>)<sub>2</sub>NCS<sub>2</sub>)<sub>3</sub>] ([InR<sub>3</sub>]) and dibutyldithiocarbamate silver(I) [Ag((C<sub>4</sub>H<sub>9</sub>)<sub>2</sub>NCS<sub>2</sub>)] ([AgR]) precursors, AgInS<sub>2</sub>-based nanoparticles with different structures have been synthesized\nin a controlled manner through a one-pot approach via different growth\nmechanisms in 1-dodecanethiol (DDT) and oleylamine (OLA), respectively.\nThe DDT and OLA could participate in the decomposition of precursors;\nthus, the [AgR]/DDT, [InR<sub>3</sub>]/DDT, [AgR]/OLA, and [InR<sub>3</sub>]/OLA were used herein to describe the decomposition steps.\nIn DDT, the decomposition activity of [AgR]/DDT was much higher than\nthat of [InR<sub>3</sub>]/DDT; thus, the sequential decomposition\nof [AgR]/DDT and [InR<sub>3</sub>]/DDT led to the formation of the\nAg<sub>2</sub>S nanoparticles intermediate first, which then reacted\nwith [InR<sub>3</sub>]/DDT to form metastable <i>o</i>-AgInS<sub>2</sub> nanoparticles via the cation exchange and alloy process,\nand finally evolved into <i>o</i>-AgInS<sub>2</sub>@InS<sub><i>x</i></sub> core@shell nanoparticles, while in OLA,\nthe decomposition activity of [AgR]/OLA was slightly higher than that\nof [InR<sub>3</sub>]/OLA. Thus, the quasi-co-decomposition of [AgR]/OLA\nand [InR<sub>3</sub>]/OLA led to the formation of Ag-rich Ag–In–S\namorphous nanoparticles intermediate first and then quickly evolved\ninto stable <i>t</i>-AgInS<sub>2</sub>/InS<sub><i>x</i></sub> nanoparticles. In addition, the photoluminescence quantum\nyield (PLQY) of <i>t</i>-AgInS<sub>2</sub>/InS<sub><i>x</i></sub> nanoparticles was higher than that of <i>o</i>-AgInS<sub>2</sub>@InS<sub><i>x</i></sub> nanoparticles.