Fabrication of Water-Soluble CuInS₂ Quantum Dots by Hot-Injection Method and Phase Transfer Strategy

Here we report an optimized hot-injection method and a phase transfer strategy for the synthesis of water-soluble CuInS₂ QDs with desired properties. The structure and morphology studies demonstrate that the resulting QDs are CuInS₂ tetragonal phase with well-defined facets. It is also found that the crystal size gradually increases with the increase of reaction temperature, while the surface of QDs with pre- and post-phase transfer is functionalized with hydrophobic and hydrophilic ligands, respectively. Spectroscopy measurements reveal the size-dependent optical properties of CuInS₂ QDs, demonstrating the quantum confinement effect in this system.