Shape-controlled synthesis of CdSe tetrapods using cationic surfactant ligands

CdSe tetrapods with high shapes and dimensional uniformity was synthesized using quaternary ammonium surfactant ligands. Tetrapods can be synthesized with high shape selectivity and high size uniformity without selective precipitation. Precursor concentration and injection sequence were used in synthesis to provide other synthesis parameters for shape control. Trioctylphosphine selenide was injected into an octadecene (ODE) solution of CdO and oleic acid (OA) for synthesis. Cetyltrimethylammonium bromide (CTAB) was alos used to synthesize CdSe tetrapods. The quat was introduced into the synthesis by combining it with the Se solution before injection at 300°C. The particles were grown at 280°C, and recovered and washed with acetone. X-ray diffraction (XRD) analysis was performed to analyze the quat ligands. Results show that CTAB and DDAB lead to the formation of CdSe tetrapods with high shape selectivity and uniformity.