Superassembling of Bi2Te3 hierarchical nanostructures for enhanced thermoelectric performance

Abstract

We describe a facile and one-step pulsed laser deposition (PLD) technique that was utilized for the first time to systematically fabricate a series of innovative Bi₂Te₃ superassembly-on-epitaxy bi-layer nanostructures, by uniquely coupling the upper self-assembled well-ordered Bi₂Te₃ hierarchical nanostructures with unusually high surface- and interface-to-volume ratios and a highly electrical conductive epitaxial bottom thin layer on insulated SiO₂/Si substrates, as an emerging new class of the most advanced thermoelectric nanomaterials. The optimized power factor of the present superassembly-on-epitaxy films is one to three orders of magnitude higher than that of most Bi₂Te₃ nanoassemblies defined as the assemblies of nanocrystals, evidently proving the significance and potential of the present new concept and the resulting thermoelectric nanomaterials.