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

Abstract

In this report, Cu_2−xSe nanoplates with columnar superstructures have been synthesized via a facile, “green”, phosphine-free, low-cost colloidal method. An inorganic tin(IV) selenium complex (Sn₂Se₆)⁴⁻ was attached on the surfaces of Cu_2−xSe nanoplates directly during the synthesis of Cu_2−xSe nanoplates. With the assistance of (Sn₂Se₆)⁴⁻ complexes, Cu_2−xSe nanoplates showed “strong” self-assembly behavior and the stability of Cu_2−xSe 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−xSe superstructures had been studied. We found the “strong” self-assemblies of Cu_2−xSe 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−xSe superstructure but also greatly improved their superior electrical property.