Facile Synthesis of Straight and Branched CdTe Nanowires Using CdO as Precursor

Abstract

High-quality colloidal CdTe nanowires (NWs) containing both straight and branched ones were controllably prepared via a solution-based approach, using a low melting Bi nanoparticles as catalysts, CdO and tributylphosphine telluride (TBP-Te) as precursors, and a tri-n-octylphosphine oxide/trin-octylphosphine (TOPO/TOP) mixture as solvent. The resulting straight CdTe NWs have typical diameters below 20 nm accompanying with lengths exceeding 10 m. In the case of branched CdTe NWs, tripod, V -shaped and y -shaped morphologies are obtained by decreasing the apparent Cd/Te molar ratio. It is found that, as the surface capping ligands, di-n-octylphosphinic acid (DOPA) is superior to decylphosphonic acid (DPA) in the reproducible growth of high-quality CdTe NWs. Since highly toxic dimethylcadmium, a cadmium precursor widely used in literatures, is replaced by CdO and the amount of the TOPO/TOP solvent mixture is significantly reduced, a relative safe and economical synthetic approach of high-quality colloidal CdTe NWs with controllable morphology is thus presented.