Fabrication of “strong” columnar Cu2−xSe superstructures assisted by inorganic ligands

In this report, Cu(2-x)Se nanoplates with columnar superstructures have been synthesized via a facile, "green", phosphine-free, low-cost colloidal method. An inorganic tin(iv) selenium complex (Sn(2)Se(6))(4-) was attached on the surfaces of Cu(2-x)Se nanoplates directly during the synthesis of Cu(2-x)Se nanoplates. With the assistance of (Sn(2)Se(6))(4-) complexes, Cu(2-x)Se nanoplates showed "strong" self-assembly behavior and the stability of Cu(2-x)Se nanoplate superstructures was increased. Such columnar superstructures were still kept even if most of the coordinating organic ligands were removed by washing. The mechanism of the formation of "strong" columnar Cu(2-x)Se superstructures had been studied. We found the "strong" self-assemblies of Cu(2-x)Se nanoplates were formed only with the coexistence of oleylamine (OAM) and Sn-X in the synthesis process. The inorganic ligand not only played a key role in the construction of the "strong" columnar Cu(2-x)Se superstructure but also greatly improved their superior electrical property.