Synthesis of periodic hexagonal surfactant templated platinum tin tellurides: Narrow band gap inorganic/organic composites

In this work we report the synthesis and characterization of a new nanostructured platinum/tin/ telluride inorganic/surfactant composite. The material is synthesized from soluble SnTe4(4-) clusters and is shown to have well-defined nanometer scale periodicity along with unique optical properties. Small-angle X-ray scattering indicates that the material forms with a 2D hexagonal honeycomb structure, which is size tunable based on surfactant tail length. Multinuclear EXAFS is used as a probe of local order in these materials. The results indicate that the tetrahedral SnTe4 unit dimerizes during assembly, and these clusters are coordinated to square planar platinum ions. Near-IR/visible reflectance spectroscopy indicates that the material is a narrow band gap semiconductor with a band gap of 0.8 eV. The extension of the ideas of surfactant templating to a narrow band gap semiconductor opens up the exciting potential for future optoelectronic applications.