Solution−Liquid−Solid Growth of Ternary Cu−In−Se Semiconductor Nanowires from Multiple- and Single-Source Precursors

Abstract

Ternary CuInSe₂ nanowires were synthesized for the first time by the solution−liquid−solid (SLS) mechanism. Here, both metal−organic multiple- and single-source molecular precursors were thermally decomposed in the presence of molten metal nanoparticles and coordinating ligands. The nature of the precursor—multiple- compared to single-source (wherein Cu−Se−In bonds are effectively preformed)—as well as the choice of coordinating ligands, reaction temperature, and reactant order-of-addition strongly affected the morphology and composition of the reaction product obtained. Crystalline, straight, and nearly stoichiometric CuInSe₂ nanowires were most readily achieved using the single-source precursor; however, careful tuning of reaction conditions could also be used to obtain high-quality nanowires from multiple-source precursor systems. The CuInSe₂ nanowires are strong light absorbers from the near-infrared through the visible and ultraviolet spectral regions and, thereby, comprise new soluble and processable “building blocks” for applications in solar-light harvesting.