Low-temperature synthesis of tetrapod CdSe/CdS quantum dots through a microfluidic reactor

Abstract

Tetrapod CdSe/CdS quantum dots (QDs) have attracted extensive research interest in light-emitting applications due to their anisotropic optical properties and large absorption cross-section. Traditional synthesis methods for tetrapod CdSe/CdS QDs usually employ fatty phosphonic acid ligands to induce the growth of wurtzite CdS arms on cubic CdSe QDs at high temperatures (350–380 °C). Here, a low temperature (120 °C) route was developed for the synthesis of tetrapod CdSe/CdS QDs using mixed amine ligands instead of phosphonic acid ligands. A study of the growth mechanism reveals that the amine ligands induce the orientation growth of cubic CdS arms on wurtzite CdSe QDs through a pyramid-shaped intermediate structure. The low reaction temperature facilitates the growth control of the tetrapod CdSe/CdS QDs through a microfluidic reactor. This study substantially simplifies the synthetic chemistry for the anisotropic growth of CdS on CdSe QDs, paving the way for green and economic production of tetrapod CdSe/CdS QDs towards efficient light-emitting applications.