The General Synthesis of Nanostructured V/VI Semiconductors

ABSTRACTSemiconductors in the V/VI series have band gaps ranging from 2.2 eV for Sb2S3 to 0.21 eV for Bi2Te3 spanning the range seen from conventional mid to narrow band gap materials to semi-metals. These materials, especially those with narrower band gaps, demonstrate thermo-electric properties and are used in Peltier devices. There are examples in the literature of the synthesis of several of these materials in a nanostructured form, however the reactions often rely on highly toxic reagents, especially in the case of tellurium containing materials. Further more there are no reports of general routes applicable to all three chalcogenides.In this paper we describe a general method for the synthesis of chalcogenide V/VI nanomaterials by the reaction of acetate salts with the corresponding chalcogenide under reflux conditions in long chain alkyl amines, typically octylamine or dodecylamine. The effect of temperature and capping agent on the morphology of the final product are discussed and in particular the synthesis of Bi2S3 nanorods, Bi2Se3 and Bi2Te3 nanowafers and Sb2Se3 nanowires are described.