A nanoscale heterostructure tellurium-based nanowire structure, including a rod-like tellurium nanowire structure and a metal telluride agglomeration connected to the rod-like nanowire structure. The metal telluride agglomeration may have an octahedral shape or a platelet shape. The agglomeration structures are selected from the group comprising lead telluride, cadmium telluride, bismuth telluride, and combinations thereof.
 The invention was made with government support under contract number CBET1048616 awarded by the National Science Foundation/Department of Energy Thermoelectric Partnership. The government has certain rights in the invention.