Shashlik-Like Te-Bi2Te3 Hetero-nanostructures: One-pot Synthesis, Growth Mechanism and Their Thermoelectric Properties
Shashlik-like Te-Bi2Te3 nanocomposites (consisting of Te nanorods and Bi2Te3 nanoplates) were successfully synthesized via a solvothermal method. Te nanorods first appear in the solvent followed by the formation of Bi2Te3 nanoplates on the surface of the Te nanorods. The lattice parameters of the Te phase and Bi2Te3 phase are almost identical (aBi2Te3 ≈ aTe, ϲBi2Te3 ≈ 5cTe), resulting in epitaxial growth of the nanoplates and ultimately forming the shashlik-like structure. With increasing reaction time, the Te nanorods gradually dissolved, and only pure Bi2Te3 nanoplates remained. The effect of different reaction times on crystal growth and the morphology evolution of products are extensively discussed. The Te-Bi2Te3 hetero-nanostructure powders were then densified to a bulk material by a spark plasma sintering technique, showing a promising figure of merit (ZT) value (0.54, 398 K). This study explores and provides a reliable one-pot method to synthesize novel shashlik-like Te-Bi2Te3 for high-performance thermoelectric materials application.